Laird Connectivity AC4490 RF Transceiver Module User Manual AC4490 AC4486 User s Manual v1 6

AeroComm Corporation RF Transceiver Module AC4490 AC4486 User s Manual v1 6

Users Manual Part 1

AC4490 900 MHz OEM TRANSCEIVERS Specifications Subject to Change User’s Manual Version 1.6 10981 EICHER DRIVE LENEXA, KS 66219 (800) 492-2320 www.aerocomm.com wireless@aerocomm.com
11/07/03 2 DOCUMENT INFORMATION Copyright Information Copyright © 2003 AEROCOMM, Inc. All rights reserved. The information contained in this manual and the accompanying software programs are copyrighted and all rights are reserved by AEROCOMM, Inc. AEROCOMM, Inc. reserves the right to make periodic modifications of this product without obligation to notify any person or entity of such revision. Copying, duplicating, selling, or otherwise distributing any part of this product or accompanying documentation/software without the prior consent of an authorized representative of AEROCOMM, Inc. is strictly prohibited. All brands and product names in this publication are registered trademarks or trademarks of their respective holders. This material is preliminary Information furnished by AEROCOMM in this specification is believed to be accurate. Devices sold by AEROCOMM are covered by the warranty and patent indemnification provisions appearing in its Terms of Sale only. AEROCOMM makes no warranty, express, statutory, and implied or by description, regarding the information set forth herein. AEROCOMM reserves the right to change specifications at any time and without notice. AEROCOMM’s products are intended for use in normal commercial and industrial applications. Applications requiring unusual environmental requirements such as military, medical life-support or life-sustaining equipment are specifically not recommended without additional testing for such application.
11/07/03 3 DOCUMENT INFORMATION
11/07/03 4 TABLE OF CONTENTS 1. OVERVIEW ......................................................................................................................................................7 2. AC4490/AC4486 SPECIFICATIONS.........................................................................................................8 3. SPECIFICATIONS..........................................................................................................................................9 3.1 INTERFACE SIGNAL DEFINITIONS......................................................................................................................9 3.2 ELECTRICAL SPECIFICATIONS..........................................................................................................................10 3.3 SYSTEM TIMING..................................................................................................................................................11 3.3.1 Serial Interface Data Rate.....................................................................................................................11 3.3.2 Timing Diagrams.....................................................................................................................................11 3.3.3 Maximum Overall System Throughput................................................................................................14 4. CONFIGURING THE AC4490/AC4486.................................................................................................15 4.1 EEPROM PARAMETERS...................................................................................................................................15 4.2 EEPROM CONFIGURATION COMMANDS.......................................................................................................18 4.2.1 EEPROM Byte Read ...............................................................................................................................18 4.2.2 EEPROM Byte Write...............................................................................................................................18 4.2.3 EEPROM Exit Configuration Mode Command.................................................................................19 4.3 AC4490 AT COMMANDS..................................................................................................................................19 4.3.1 Enter AT Command Mode......................................................................................................................19 4.3.2 Exit AT Command Mode........................................................................................................................20 4.4 ON-THE-FLY CONTROL COMMAND REFERENCE (CC COMMAND MODE)................................................20 4.4.1 Status Request..........................................................................................................................................21 4.4.2 Change Channel without Forced Acquisition Sync...........................................................................21 4.4.3 Change Channel with Forced Acquisition Sync.................................................................................21 4.4.4 Server/Client Command.........................................................................................................................22 4.4.5 Sync to Channel Command....................................................................................................................22 4.4.6 Sleep Walk Power-Down Command....................................................................................................23 4.4.7 Sleep Walk Power-Down Wake-Up Command ..................................................................................23 4.4.8 Broadcast Mode.......................................................................................................................................23 4.4.9 Read Static Bank #1 Byte.......................................................................................................................24 4.4.10 Write Static Bank #1 Byte......................................................................................................................24 4.4.11 Read Static Bank #2 Byte.......................................................................................................................24 4.4.12 Write Static Bank #2 Byte......................................................................................................................26 4.4.13 Write Destination Address.....................................................................................................................26 4.4.14 Read Destination Address......................................................................................................................26 4.4.15 Read Digital Inputs.................................................................................................................................27 4.4.16 Read ADC .................................................................................................................................................27 4.4.17 Report Last Valid RSSI...........................................................................................................................28 4.4.18 Write Digital Outputs..............................................................................................................................28 4.4.19 Write DAC ................................................................................................................................................29 4.4.20 Set Max Power.........................................................................................................................................29 4.4.21 Transmit Buffer Empty............................................................................................................................30 4.4.22 Disable Sync to Channel ........................................................................................................................30 4.4.23 Deep Sleep Mode.....................................................................................................................................30 4.4.24 Reset Command .......................................................................................................................................30 5. THEORY OF OPERATION.......................................................................................................................31 5.1 HARDWARE INTERFACE.....................................................................................................................................31 5.1.1 GIn (Generic Inputs 0 and 1) (pins 4 and 14 respectively) and GOn (Generic Outputs 0 and 1) (pins 1 and 9 respectively).......................................................................................................................................31 5.1.2 TXD (Transmit Data) and RXD (Receive Data) (pins 2 and 3 respectively)................................31
11/07/03 5 5.1.3 Hop Frame (pin 6)...................................................................................................................................31 5.1.4 CTS Handshaking (pin 7).......................................................................................................................32 5.1.5 RTS Handshaking (pin 8).......................................................................................................................32 5.1.6 9600 Baud (pin 12)..................................................................................................................................32 5.1.7 RSSI (pin 13)............................................................................................................................................32 5.1.8 UP_Reset (pin 15) ...................................................................................................................................33 5.1.9 Command/Data (pin 17).........................................................................................................................33 5.1.10 AD In and DA Out (pins 18 and 19 respectively) ..............................................................................34 5.1.11 In Range (pin 20).....................................................................................................................................34 5.2 SOFTWARE PARAMETERS..................................................................................................................................35 5.2.1 RF Architecture (Unicast/Broadcast)..................................................................................................35 5.2.2 RF Mode....................................................................................................................................................35 5.2.3 Sub Hop Adjust ........................................................................................................................................36 5.2.4 Duplex Mode............................................................................................................................................36 5.2.5 Interface Timeout/RF Packet Size........................................................................................................36 5.2.6 Serial Interface Baud Rate.....................................................................................................................37 5.2.7 Network Topology...................................................................................................................................37 5.2.8 Auto Config...............................................................................................................................................39 5.2.9 One Beacon Mode...................................................................................................................................40 5.2.10 Max Power................................................................................................................................................41 5.2.11 Interface Options.....................................................................................................................................42 6. DIMENSIONS.................................................................................................................................................44 7. ORDERING INFORMATION...................................................................................................................47 7.1 PRODUCT PART NUMBER TREE........................................................................................................................47 7.2 DEVELOPER KIT PART NUMBERS....................................................................................................................47 8. AGENCY COMPLIANCY INFORMATION........................................................................................48 8.1 AGENCY IDENTIFICATION NUMBERS...............................................................................................................48 8.2 APPROVED ANTENNA LIST ...............................................................................................................................48 8.3 FCC/INDUSTRY CANADA (IC) REQUIREMENTS FOR MODULAR APPROVAL............................................49 8.3.1 OEM Equipment Labeling Requirements............................................................................................49 8.3.2 Antenna Requirements............................................................................................................................50 8.3.3 Warnings Required in OEM Manuals..................................................................................................50 RF Exposure Warning for Portable Equipment (<2.5cm) .................................................................................50 RF Exposure Warning for Portable Equipment (>2.5cm) .................................................................................50 RF Exposure for Warning for Mobile Equipment................................................................................................50 8.4 EUROPE/ETSI REQUIREMENTS FOR MODULAR APPROVAL........................................................................50 Figures Figure 1 – RSSI Voltage vs. Received Signal Strength.......................................................................................... 33 Figure 2 - AC4490/AC4486 (with MMCX Connector) Mechanical.................................................................... 44 Figure 3 - AC4490 (with Integral GigaAnt Antenna) Mechanical........................................................................ 45 Figure 4 - AC4490/AC4486 (with Integral Splatch Antenna) Mechanical......................................................... 45 Tables Table 1 – Pin Definitions................................................................................................................................................ 9 Table 2 – Input Voltage Characteristics (AC4490/AC4486 500mW).................................................................. 10 Table 3 – Input Voltage Characteristics (All Others).............................................................................................. 10 Table 4 – Output Voltage Characteristics (All) ........................................................................................................ 10 Table 5 – Supported Serial Formats ........................................................................................................................... 11 Table 6 – Timing Parameters ....................................................................................................................................... 13 Table 7 – Maximum Overall System Throughputs.................................................................................................. 14
11/07/03 6 Table 8 – EEPROM Parameters .................................................................................................................................. 15 Table 9 – Baud Rate/Interface Timeout..................................................................................................................... 37 Table 10 – US and International RF Channel Number Settings............................................................................ 38 Table 11 – Auto Config Parameters ........................................................................................................................... 40 Table 12 – Max Power Settings for 5mW Transmitter ......................................... Error! Bookmark not defined. Table 13 – Max Power Settings for 100mW Transmitter....................................................................................... 41 Table 14 – Max Power Settings for 500mW Transmitter....................................................................................... 41 Table 15 – Transceiver Interface to DCE (Server Radio)....................................................................................... 43 Table 16 – Transceiver Interface to DTE (Client Radio)........................................................................................ 43 Table 17 – Agency Identification Numbers .............................................................................................................. 48 Table 18 – AC4490/AC4486 Approved Antenna List............................................................................................ 48
AC4490/AC4486 Specifications 11/07/03 7 AC4490/AC4486 Features ?? Available in either 3.3V or 5V TTL level serial interface for fast integration ?? Drop-in replacement for AC4424 2.4GHz product family ?? Two generic input and output digital lines and integrated DAC/ADC functions ?? Frequency Hopping Spread Spectrum for security and interference rejection ?? Cost Efficient for high volume applications ?? Very low power consumption for battery powered implementations ?? Small size for portable and enclosed applications ?? Very Low latency and high throughput ?? All modules are qualified for Industrial temperatures (-40°C to 80°C) 1. Overview The AC4490/AC4486 and AC4486 are members of AeroComm’s ConnexRF OEM transceiver family. The AC4490 is designed for integration into OEM systems operating under FCC part 15.247 regulations for the 900 MHz ISM band. The AC4486 is designed for integration into OEM systems operating under European ETSI regulations for the 868 MHz band. The AC4490 is a cost-effective, high performance, frequency hopping spread spectrum transceiver. It provides an asynchronous TTL/RS-485 level serial interface for OEM Host communications. Communications include both system and configuration data. The Host supplies system data for transmission to other Host(s). Configuration data is stored in an on-board EEPROM. All frequency hopping, synchronization, and RF system data transmission/reception is performed by the transceiver. These transceivers can be used as a direct serial cable replacement – requiring no special Host software for operation. They also feature a number of On-the-Fly Control Commands providing the OEM with a very versatile interface for any network. AC4490/AC4486 transceivers operate in a Point-to-Point or Point-to-Multipoint, Client-Server or Peer-to-Peer architecture. One transceiver is configured as a Server and there can be one or many Clients. To establish synchronization between transceivers, the Server emits a beacon. Upon detecting a beacon, a Client transceiver informs its Host and a RF link is established. This document contains information about the hardware and software interface between an AeroComm AC4490/AC4486 transceiver and an OEM Host. Information includes the theory of operation, specifications, interface definition, configuration information and mechanical drawing. The OEM is responsible for ensuring the final product meets all FCC and/or appropriate regulatory agency requirements listed herein before selling any product.
AC4490/AC4486 Specifications 11/07/03 8 2. AC4490/AC4486 Specifications GENERAL Interface 20 pin mini-connector Serial Interface Data Rate PC baud rates from 1200 bps to 115,200 bps Power Consumption (typical) Duty Cycle (TX=Transmit; RX=Receive) 10%TX 50%TX 100%TX 100%RX Pwr-DownDeep Sleep AC4490-200:43mA 95mA 106mA 30mA 19mA 6mA AC4490-1000:126mA 508mA 985mA 30mA 19mA 6mA Channels 5 Channel Sets comprising 58 total channels Security One byte System ID. Interface Buffer Size Input/Output: 256 bytes each RADIO Frequency Band US/Canada: 902 – 928 MHz Australia: 915 – 928 MHz RF Data Rate 76.8kbps Radio Type AC4490: Frequency Hopping Spread Spectrum Output Power (conducted, no antenna) AC4490-200: 100mW typical AC4490-1000: 1000mW Effective Isotropic Radiated Power (EIRP with 3dBi gain antenna) AC4490-200: 200mW typical AC4490-1000: 1000mW Supply Voltage AC4490-200: 3.3 or 3.45 - 6V ±2%, ±50mV ripple AC4490-1000: 3.3 ±2%, ±50mV ripple Sensitivity -100dBm typical @ 76.8kbps Range, Line of Site (based on 3dBi gain antenna) AC4490-200: 4 miles AC4490-1000: 20 miles ENVIRONMENTAL Temperature (Operating) -40?C to 80?C Temperature (Storage) -50?C to +85?C Humidity (non-condensing) 10% to 90% PHYSICAL Dimensions 1.65” x 1.9” x 0.20” Antenna AC4490-200: MMCX Connector or integral antenna AC4490-1000: MMCX Connector Weight Less than 0.75 ounce
AC4490/AC4486 Specifications 11/07/03 9 3. Specifications 3.1 INTERFACE SIGNAL DEFINITIONS The AC4490/AC4486 has a simple interface that allows OEM Host communications with the transceiver. Table 1 – Pin Definitions, shows the connector pin numbers and associated functions. The I/O direction is with respect to the transceiver. All outputs are 3.3VDC levels and inputs are 5VDC TTL (with the exception of 500mW radios which are 3.3V inputs) with the exception of RSSI, AD In and DA Out, which are all analog. All inputs are weakly pulled High and may be left floating during normal operation. Table 1 – Pin Definitions Pin Type Signal Name Function 1 O GO0 Generic Output pin O TXD Transmitted data out of the transceiver 2 I/O RS485 A (True)1 Noninverted RS-485 representation of serial data I RXD Data input to the transceiver 3 I/O RS485 B (Invert)2 Mirror image of RS-485 A 4 I GI0 Generic Input pin 5 GND GND Signal Ground 6 O Hop Frame Pulses Low when the transceiver is hopping. 7 O CTS Clear to Send – Active Low when the transceiver is ready to accept data for transmission. 8 I RTS Request to Send – When enabled in EEPROM, the OEM Host can take this High when it is not ready to accept data from the transceiver. NOTE: Keeping RTS High for too long can cause data loss. 9 O GO1 Generic Output pin 10 PWR VCC 3.3 or 3.45 – 6V (depends on model) ± 2%, ± 50mV ripple 11 PWR VCC 3.3 or 3.45 – 6V (depends on model) ± 2%, ±50 mV ripple 12 I 9600_BAUD 9600_BAUD – When pulled logic Low before applying power or resetting the transceiver’s serial interface is forced to a 9600, 8, N, 1 rate. To exit, transceiver must be reset or power-cycled with 9600_Baud logic High. 13 O RSSI Received Signal Strength - An analog output giving an instantaneous indication of received signal strength. Only valid while in Receive Mode. 14 I GI1 Generic Input pin 15 I UP_RESET RESET – Controlled by the AC4490/AC4486 for power-on reset if left unconnected. After a Stable power-on reset, a logic High pulse will reset the transceiver. 16 GND GND Signal Ground 17 I Command/Data When logic Low, the transceiver interprets Host data as command data. When logic High, the transceiver interprets Host data as transmit data. 18 I AD In 10 bit Analog Data Input 19 O DA Out 10 bit Analog Data Output 20 O IN_RANGE In Range – Active Low when a Client radio is in range of a Server on same Channel with the same System ID. Always Low on a Server. I = Input to the transceiver O = Output from the transceiver 1 When ordered with a RS-485 interface.
AC4490/AC4486 Specifications 11/07/03 10 3.2 ELECTRICAL SPECIFICATIONS Table 2 – Input Voltage Characteristics (AC4490/AC4486 500mW) Pin Type Name High Min. High Max. Low Min. Low Max. Unit 2,3 I/O RS485A/B V 3 I RXD 2.31 3.3 0 0.99 V 4 I GI0 2.31 3.3 0 0.99 V 8 I RTS 2.31 3.3 0 0.99 V 12 I 9600_Baud 2.31 3.3 0 0.99 V 14 I GI1 2.31 3.3 0 0.99 V 15 I UP_RESET 0.8 3.3 0 0.6 V 17 I Command/Data 2.31 3.3 0 0.99 V 18 I AD In N/A 3.3 0 N/A V Table 3 – Input Voltage Characteristics (All Others) Pin Type Name High Min. High Max. Low Min. Low Max. Unit 2,3 I/O RS485A/B V 3 I RXD 2 5.5 0 0.8 V 4 I GI0 2 5.5 0 0.8 V 8 I RTS 2 5.5 0 0.8 V 12 I 9600_Baud 2 5.5 0 0.8 V 14 I GI1 2 5.5 0 0.8 V 15 I UP_RESET 0.8 5 0 0.6 V 17 I Command/Data 2 5.5 0 0.8 V 18 I AD In N/A 3.3 0 N/A V Table 4 – Output Voltage Characteristics (All) Pin Type Name High Min. Low Max. Unit 1 O GO0 2.5 @ 8mA 0.4 @ 8mA V 2 O TXD 2.5 @ 2mA 0.4 @ 2mA V 2,3 I/O RS485A/B V 6 O Hop Frame 2.5 @ 2mA 0.4 @ 2mA V 7 O CTS 2.5 @ 2mA 0.4 @ 2mA V 9 O GO1 2.5 @ 2mA 0.4 @ 2mA V 13 O RSSI See Figure 1 See Figure 1 V 19 O AD Out N/A N/A V2 20 O IN_RANGE 2.5 @ 2mA 0.4 @ 2mA V 2 AD Out is an unbuffered, high impedance output and must be buffered by the OEM Host when used.
AC4490/AC4486 Specifications 11/07/03 11 3.3 SYSTEM TIMING Care should be taken when selecting transceiver architecture as it can have serious effects on data rates, latency timings, and overall system throughput. The importance of these three characteristics will vary from system to system and should be a strong consideration when designing the system. 3.3.1 Serial Interface Data Rate The Serial Interface Data Rate is programmable by the Host. This is the rate the Host and transceiver communicate over the serial bus. Possible values range from 1200 bps to 115,200 bps. The following asynchronous serial data formats are supported: Table 5 – Supported Serial Formats Data Bits Parity Minimum Stop Bits Required Radio Programming Requirements 8 N 1 Parity Mode disabled 8 E,O,M,S 1 Parity Mode enabled 7 E,O,M,S 1 Parity Mode disabled 3.3.2 Timing Diagrams Stream Mode with Interface Timeout: Local_RXDLocal_RF_TXDRemote_RF_TXDRemote_TXDHop_FramePacket DataReceived DataRF PacketsHop TimeWait for HopInterface TimeoutHop Period
AC4490/AC4486 Specifications 11/07/03 12 Stream Mode with Fixed Packet Length: Addressed Acknowledge Mode with Interface Timeout: Addressed Acknowledge Mode with No Interface Timeout: Local_RXDLocal_RF_TXDRemote_RF_TXDRemote_TXDHop_FramePacket DataRF PacketReceived DataRF AcknowledgeHop TimeWait for HopHop PeriodLocal_RXDLocal_RF_TXDRemote_RF_TXDRemote_TXDHop_FramePacket DataRF PacketReceived DataRF AcknowledgeHop TimeHop PeriodInterface TimeoutWait for HopLocal_RXDLocal_RF_TXDRemote_RF_TXDRemote_TXDHop_FramePacket DataReceived DataRF PacketsHop TimeWait for HopHop Period
AC4490/AC4486 Specifications 11/07/03 13 Broadcast Acknowledge Mode with No Interface Timeout: Broadcast Acknowledge Mode with Interface Timeout: Table 6 – Timing Parameters Parameter Typical Time (ms) Hop Time 1 Hop Period 20 Local_RXDLocal_RF_TXDRemote_RF_TXDRemote_TXDHop_FramePacket DataRF PacketReceived DataHop TimeWait for HopHop PeriodLocal_RXDLocal_RF_TXDRemote_RF_TXDRemote_TXDHop_FramePacket DataRF PacketReceived DataHop TimeHop PeriodInterface TimeoutWait for Hop
AC4490/AC4486 Specifications 11/07/03 14 3.3.3 Maximum Overall System Throughput When configured as shown in the table below, an AC4490/AC4486 transceiver is capable of achieving the listed throughput. However, in the presence of interference or at longer ranges, the transceiver might not be able to meet these specified throughputs. Table 7 – Maximum Overall System Throughputs RF Mode One Beacon Mode Throughput (bps) Half Duplex Throughput (bps) Full Duplex Stream Disabled 57.6k N/A Acknowledge Enabled 48k 24k Acknowledge Disabled 38k 19k
AC4490/AC4486 Specifications 11/07/03 15 4. Configuring the AC4490 4.1 EEPROM PARAMETERS A Host can program various parameters that are stored in EEPROM and become active after a power-on reset. Table 7 - EEPROM Parameters, gives the locations and descriptions of the parameters that can be read or written by a Host. Factory default values are also shown. Do not write to any EEPROM addresses other than those listed below. Do not copy a transceiver’s EEPROM data to another transceiver. Doing so may cause the transceiver to malfunction. Table 8 – EEPROM Parameters Parameter EEPROM Address Length (Bytes) Range Default Description Product ID 00h 40 40 bytes - Product identifier string. Includes revision information for software and hardware. Sub Hop Adjust 36h 1 00 – FFh 66h This value should only be changed when recommended by Aerocomm Range Refresh 3Dh 1 00 – FFh 18h This byte specifies the maximum amount of time a transceiver will report In Range without having heard a beacon (320ms per increment). 0h is actually 256 * 320ms. Channel Number 40h 1 00 – 39h 00h Set 0 = 00 – 0Fh (US/Canada) – AC4490 Set 1 = 10 – 2Fh (US/Canada) – AC4490 Set 2 = 30 – 37h (Australia) – AC4490 Set 3 = 38h (Europe 500mW) – AC4486 Set 4 = 39h (Europe 5mW) – AC4486 Server/Client Mode 41h 1 01 – 02h 02h 01h = Server 02h = Client Baud Rate Low 42h 1 00 – FFh FCh Low Byte of the interface baud rate. Baud Rate High 43h 1 00h 00h Always 00h
AC4490/AC4486 Specifications 11/07/03 16 Parameter EEPROM Address Length (Bytes) Range Default Description Control 0 45h 1 00010100b (14h) Settings are: Bit 7 – One Beacon 0 = Beacon every hop 1 = Beacon once per hop cycle Bit 6 – AeroComm Use Only Bit 5 – Sync to Channel 0 = Don't Sync to Channel 1 = Sync to Channel Bit 4 – AeroComm Use Only Bit 3 – AeroComm Use Only Bit 2 – RF Mode 0 = RF Stream Mode 1 = RF Acknowledge Mode Bit 1 – RF Delivery 0 = Addressed 1 = Broadcast Bit 0 – AeroComm Use Only Frequency Offset 46h 1 00 – FFh 01h Protocol parameter used in conjunction with Channel Number. Transmit Retries 4Ch 1 01 – FFh 10h Maximum number of times a packet is sent out in Addressed Acknowledge mode. Broadcast Attempts 4Dh 1 01 – FFh 04h Number of times a packet is sent out in Broadcast Acknowledge mode. API Control 56h 1 01000011b (43h) Settings are: Bit 7 – AeroComm Use Only Bit 6 – AeroComm Use Only Bit 5 – Unicast Only 0 = Receive Unicast and Broadcast packets 1 = Only receive Unicast packets Bit 4 – Auto Destination 0 = Use Destination Address 1 = Set Destination to Server Bit 3 – AeroComm Use Only Bit 2 – RTS Enable 0 = RTS Ignored 1 = Transceiver obeys RTS Bit 1 – Duplex Mode 0 = Half Duplex 1 = Full Duplex Bit 0 – Auto Config 0 = Use EEPROM values 1 = Auto Configure Values Interface Timeout 58h 1 02 – FFh 04h Specifies a byte gap timeout, used in conjunction with RF Packet Size, to determine when a packet is complete (0.5ms per increment). Sync Channel 5Ah 1 00 – 3Fh 01h Used to synchronize the hopping of collocated systems to minimize interference.
AC4490/AC4486 Specifications 11/07/03 17 Parameter EEPROM Address Length (Bytes) Range Default Description RF Packet Size 5Bh 1 01 – FFh 46h Specifies the maximum size of an RF packet. CTS On 5Ch 1 01 – FFh D2h CTS will be deasserted (High) when the transmit buffer contains at least this many characters. CTS On Hysteresis 5Dh 1 00 – FEh ACh Once CTS has been deasserted, CTS will be reasserted (Low) when the transmit buffer contains this many or less characters. Max Power 63h 1 00 – FFh 60h Used to increase or decrease transmit power output. Modem Mode 6Eh 1 E3h, FFh FFh E3h = Enable Modem Mode FFh = Disable Modem Mode Parity Mode 6Fh 1 E3h, FFh FFh E3h = Enable Parity Mode FFh = Disable Parity Mode RS-485 DE 7Fh 1 E3h, FFh FFh E3h = GO0 is active Low DE for control of external RS-485 hardware. FFh = Disable RS-485 DE mode Destination ID 70h 6 Specifies destination for RF packets. System ID 76h 1 00 – FFh 01h Similar to a network password. MAC ID 80h 6 Unique IEEE MAC Address.
AC4490/AC4486 Specifications 11/07/03 18 4.2 EEPROM CONFIGURATION COMMANDS The configuration set allows the Host to modify the operation of the transceiver. If the Command/Data pin (Pin 17) is pulled logic Low, a transceiver will interpret incoming Host data as Command Data. The Host can then read and write parameters using the various configuration commands listed below. To exit Configuration Mode, the Host must perform a hardware or power-on reset or issue an Exit Command Mode command to the transceiver. While in Configuration Mode, the RF circuitry will be disabled. 4.2.1 EEPROM Byte Read Upon receiving this command, a transceiver will transmit the desired data from the address requested by the Host. Host Command: Byte 1 = C0h Byte 2 = Address Byte 3 = Length (01…FFh = 1…255 bytes; 00h = 256 bytes) Transceiver Response: Byte 1 = C0h Byte 2 = Address Byte 3 = Length Byte 4…n = Data at requested address(s) 4.2.2 EEPROM Byte Write Upon receiving this command, a transceiver will write the data byte to the address specified but will not echo it back to the Host until the EEPROM write cycle is complete. The write can take as long as 10ms to complete. Following the write cycle, a transceiver will transmit the data byte to the Host. Multiple byte EEPROM writes are allowed up to a length of 128 bytes. An EEPROM boundary exists between addresses 7Fh and 80h. No single EEPROM write command shall write to addresses on both sides of that EEPROM boundary. Host Command: Byte 1 = C1h Byte 2 = Address Byte 3 = Length (01 – 80h) Byte 4…n = Data to store at Address Transceiver Response: Byte 1 = C1h Byte 2 = Address Byte 3 = Length (01 – 80h) Byte 4 = Last data byte written by this command
AC4490/AC4486 Specifications 11/07/03 19 4.2.3 EEPROM Exit Configuration Mode Command The OEM Host can cause the transceiver to exit Configuration Mode by issuing the Exit Configuration Mode command to the transceiver. However, the transceiver will not reflect any of the changes programmed into the EEPROM until the transceiver is reset. Host Command: Byte 1 = 56h Transceiver Response: Byte 1 = 56h 4.3 AC4490 AT COMMANDS The AT Command mode implemented in AC4490 firmware version 3.2 and higher creates a virtual version of the Command/Data line. The Enter AT Command mode command asserts this virtual line Low (to signify Command mode) and the Exit AT Command mode command asserts this virtual line High (to signify Data mode). Once this line has been asserted Low, all on-the-fly CC Commands documented in the manual are supported. When in AT Command mode, the transceiver will maintain synchronization with the network, but RF packets will not be received. However, an ambiguity of approximately 10ms exists where, if the Enter AT Command mode command has been sent to the transceiver at the same time an RF packet is being received, the RF packet could be sent to the OEM Host before the AT Command mode command response is sent to the host. 4.3.1 Enter AT Command Mode Prior to sending the Enter AT Command mode command to the transceiver, the host must ensure that the RF transmit buffer of the transceiver is empty (if the buffer is not empty, the Enter AT Command Mode command will be interpreted as packet data and transmitted out over the RF). This can be accomplished by waiting up to one second between the last transmit packet and the AT Command. The host must also ensure that the Fixed Packet Length for the transceiver is set to a minimum of six. The Enter AT Command Mode command is as follows: Host Command: AT+++? Hexadecimal Representation of the Command: 41h, 54h, 2Bh, 2Bh, 2Bh, 0Dh Transceiver Response: CCh COM Hexadecimal Representation of the Command: CCh, 43h, 4Fh, 4Dh
AC4490/AC4486 Specifications 11/07/03 20 4.3.2 Exit AT Command Mode To exit AT Command mode, the OEM host should send the following command to the transceiver: Host Command: CCh ATO? Hexadecimal Representation of the Command: CCh, 41h, 54h, 4Fh, 0Dh Transceiver Response: CCh DAT Hexadecimal Representation of the Command: CCh, 44h, 41h, 54h 4.4 ON-THE-FLY CONTROL COMMAND REFERENCE (CC COMMAND MODE) The AC4490/AC4486 transceiver contains static memory that holds many of the parameters that control the transceiver operation. Using the “CC” command set allows many of these parameters to be changed during system operation. Because the memory these commands affect is static, when the transceiver is reset, these parameters will revert back to the settings stored in the EEPROM. Note: Do not to modify undocumented static addresses as undesired operation may occur. All “CC” commands must be issued from the Host to the transceiver with Command/Data (Pin 17) pulled logic Low. To exit “CC” mode, simply take the Command/Data pin High. While in CC Command mode, the RF interface of the radio is still active. Therefore, it can receive packets from remote radios while in CC Command mode and forwards these to the OEM Host. The transceiver uses Interface Timeout to determine when a CC Command is complete. Therefore, there should be no delay between each character as it is sent from the OEM Host to the transceiver or the transceiver will not recognize the command and will enter Configuration Mode by default. If the OEM Host has sent a CC Command to the transceiver and a RF packet is received by the transceiver, the transceiver will send the CC Command response to the OEM Host before sending the packet. However, if a RF packet is received before the Interface Timeout expires on a CC Command, the transceiver will send the packet to the host before sending the CC Command response.
AC4490/AC4486 Specifications 11/07/03 21 4.4.1 Status Request The Host issues this command to request the status of the transceiver. Host Command: Byte 1 = CCh Byte 2 = 00h Byte 3 = 00h Transceiver Response: Byte 1 = CCh Byte 2 = Firmware version number Byte 3 = Data1 Where: Data1 = 00 for Server in Normal Operation 01 for Client in Normal Operation 02 for Server in Acquisition Sync 03 for Client in Acquisition Sync 4.4.2 Change Channel without Forced Acquisition Sync The Host issues this command to change the channel of the transceiver. The transceiver will not begin acquisition sync until its Range Refresh timer expires; therefore it is recommended that the host uses the Change Channel with Forced Acquisition Sync Command. Host Command: Byte 1 = CCh Byte 2 = 01h Byte 3 = RF Channel Number (Hexadecimal) Transceiver Response: Byte 1 = CCh Byte 2 = RF Channel Number (Hexadecimal) 4.4.3 Change Channel with Forced Acquisition Sync The Host issues this command to change the channel of the transceiver and force the transceiver to immediately begin synchronization. Host Command: Byte 1 = CCh Byte 2 = 02h Byte 3 = RF Channel Number (Hexadecimal) Transceiver Response: Byte 1 = CCh Byte 2 = RF Channel Number (Hexadecimal)
AC4490/AC4486 Specifications 11/07/03 22 4.4.4 Server/Client Command The Host issues this command to change the mode (Server or Client) of the transceiver and can force the transceiver to actively begin synchronization. The transceiver will not begin acquisition sync until its Range Refresh timer expires; therefore it is recommended that the host uses the commands which force acquisition sync. Host Command: Byte 1 = CCh Byte 2 = 03h Byte 3 = Data1 Where: Data1 = 00 for Server in Normal Operation 01 for Client in Normal Operation 02 for Server in Acquisition Sync 03 for Client in Acquisition Sync Transceiver Response: Byte 1 = CCh Byte 2 = Software Version Number Byte 3 = Data1 Where: Data1 = Data1 from Host Command 4.4.5 Sync to Channel Command The Host issues this command to change the Sync Channel byte and enable Sync to Channel. Host Command: Byte 1 = CCh Byte 2 = 05h Byte 3 = Data1 Where: Data1 = New Sync Channel Transceiver Response: Byte 1 = CCh Byte 2 = 05h Byte 3 = Data1 Where: Data1 = Data1 from Host Command
AC4490/AC4486 Specifications 11/07/03 23 4.4.6 Sleep Walk Power-Down Command After the Host issues the power-down command to the transceiver, the transceiver will de-assert the In_Range line after entering power-down. A Client transceiver in power-down will remain in sync with a Server for a minimum of 2 minutes. To maintain synchronization with the Server, this Client transceiver should re-sync to the Server at least once every 2 minutes. This re-sync is accomplished by issuing the Power-Down Wake-Up Command and waiting for the In Range line to go active. Once this occurs, the Client transceiver is in sync with the Server and can be put back into power-down. This command is only valid for Client radios. Host Command: Byte 1 = CCh Byte 2 = 06h Transceiver Response: Byte 1 = CCh Byte 2 = RF Channel Number 4.4.7 Sleep Walk Power-Down Wake-Up Command The Power-Down Wake-Up Command is issued by the Host to bring the transceiver out of power-down mode. Host Command: Byte 1 = CCh Byte 2 = 07h Transceiver Response: Byte 1 = CCh Byte 2 = RF Channel Number 4.4.8 Broadcast Mode The Host issues this command to change the transceiver operation between Addressed Mode and Broadcast Mode. If addressed mode is selected the transceiver will send all packets to the radio designated by the Destination Address programmed in the transceiver. Host Command: Byte 1 = CCh Byte 2 = 08h Byte 3 = 00 for addressed mode, 01 for broadcast mode Transceiver Response: Byte 1 = CCh Byte 2 = 00 for addressed mode, 01 for broadcast mode
AC4490/AC4486 Specifications 11/07/03 24 4.4.9 Read Static Bank #1 Byte The OEM Host issues this command to the transceiver to read Static Bank #1 Bytes. Static Bank #1 is a bank of memory that holds many of the parameters that control the radio. Using the Read/Write Static Bank #1 command allows these parameters to be changed dynamically. Because the memory bank is static, when the radio is reset, these parameters will revert back to the settings stored in EEPROM. Be careful not to change undocumented Static Bank addresses as undesired operation may occur. Host Command: Byte 1 = CCh Byte 2 = 0Ah Byte 3 = 00 – FFh corresponding to a valid Static Bank #1 address Transceiver Response: Byte 1 = CCh Byte 2 = 00 – FFh corresponding to a valid Static Bank #1 address 4.4.10 Write Static Bank #1 Byte The Host issues this command to the transceiver to write Static Bank #1 Bytes. Static Bank #1 is a bank of memory that holds many of the parameters that control the radio. Using the Read/Write Static Bank #1 command allows these parameters to be changed dynamically. Because the memory bank is static, when the radio is reset, these parameters will revert back to the settings stored in EEPROM. Be careful not to change undocumented Static Bank addresses as undesired operation may occur. Host Command: Byte 1 = CCh Byte 2 = 0Bh Byte 3 = 00 – FFh corresponding to a valid Static Bank #1 address Byte 4 = 00 – FFh corresponding to new value for address specified by Byte 3 Transceiver Response: Byte 1 = CCh Byte 2 = 00 – FFh corresponding to a valid Static Bank #1 address Byte 3 = 00 – FFh corresponding to new value for address specified by Byte 2 4.4.11 Read Static Bank #2 Byte The Host issues this command to the transceiver to read Static Bank #2 Bytes. Static Bank #2 is a bank of memory that holds many of the parameters that control the radio. Using the Read/Write Static Bank #2 command allows these parameters to be changed dynamically. Because the memory bank is static, when the radio is reset, these parameters will revert back to the settings stored in EEPROM. Be careful not to change undocumented Static Bank addresses as undesired operation may occur. Host Command: Byte 1 = CCh Byte 2 = 0Ch Byte 3 = 00 – FFh corresponding to a valid Static Bank #2 address Transceiver Response: Byte 1 = CCh
AC4490/AC4486 Specifications 11/07/03 25 Byte 2 = 00 – FFh corresponding to a valid Static Bank #2 address
AC4490/AC4486 Specifications 11/07/03 26 4.4.12 Write Static Bank #2 Byte The Host issues this command to the transceiver to write Static Bank #2 Bytes. Static Bank #2 is a bank of memory that holds many of the parameters that control the radio. Using the Read/Write Static Bank #2 command allows these parameters to be changed dynamically. Because the memory bank is static, when the radio is reset, these parameters will revert back to the settings stored in EEPROM. Be careful not to change undocumented Static Bank addresses as undesired operation may occur. Host Command: Byte 1 = CCh Byte 2 = 0Dh Byte 3 = 00 – FFh corresponding to a valid Static Bank #2 address Byte 4 = 00 – FFh corresponding to new value for address specified by Byte 3 Transceiver Response: Byte 1 = CCh Byte 2 = 00 – FFh corresponding to a valid Static Bank #2 address Byte 3 = 00 – FFh corresponding to new value for address specified by Byte 2 4.4.13 Write Destination Address The Host issues this command to the transceiver to change the Destination Address. This is a very powerful command that provides the OEM Host with a means for ad-hoc networking. Only the three Least Significant Bytes of the MAC Address are used for packet delivery. Host Command: Byte 1 = CCh Byte 2 = 10h Bytes 3 – 5 = 00 – FFh corresponding the three LSB’s of the destination MAC Address Transceiver Response: Byte 1 = CCh Bytes 2 – 4= 00 – FFh corresponding the three LSB’s of the destination MAC Address 4.4.14 Read Destination Address The Host issues this command to the transceiver to read the Destination Address. This is a very powerful command that provides the OEM Host with a means for ad-hoc networking. Only the three Least Significant Bytes of the MAC Address are used for packet delivery. Host Command: Byte 1 = CCh Byte 2 = 11h Transceiver Response: Byte 1 = CCh Bytes 2 – 4= 00 – FFh corresponding the three LSB’s of the destination MAC Address
AC4490/AC4486 Specifications 11/07/03 27 4.4.15 Read Digital Inputs The Host issues this command to read both digital input lines. Host Command: Byte 1 = CCh Byte 2 = 20h Transceiver Response: Byte 1 = CCh Byte 2 = Data1 Where: Data1 = bit 0 – GI0, bit 1 – GI1 4.4.16 Read ADC The Host issues this command to read any of the three onboard A/D converters. The equations for converting these 10 bits into an analog value and subsequent temperature are as follows: Analog Voltage = (10 bits / 3FFh) * 3.3V Temperature (°C) = ((Analog Voltage - 0.3) / 0.01) - 30 Host Command: Byte 1 = CCh Byte 2 = 21h Byte 3 = Data1 Where: Data1 = 00h – AD In, 01h – Temperature (if equipped), 02h – RSSI Transceiver Response: Byte 1 = CCh Byte 2 = Data1 Byte 3 = Data2 Where: Data1 = MSB of requested 10 bit ADC value Data2 = LSB of requested 10 bit ADC value
AC4490/AC4486 Specifications 11/07/03 28 4.4.17 Report Last Valid RSSI As RSSI values are only valid when the local radio is receiving a RF packet from a remote radio, instantaneous RSSI can be very tricky to use. Therefore, the transceiver stores the most recent valid RSSI value. The Host issues this command to request that value. Note: This value will default to FFh on a Client and 00h on a Server if no valid RSSI measurement has been made since power-up. To convert this byte into an analog voltage, the following equation should be used: 8 bit RSSI Voltage = (8 bits / FFh) * 3.3V Host Command: Byte 1 = CCh Byte 2 = 22h Transceiver Response: Byte 1 = CCh Byte 2 = Data1 Where: Data1 = Most significant 8 bits of last valid RSSI reading. 4.4.18 Write Digital Outputs The Host issues this command to write both digital output lines to particular states. Host Command: Byte 1 = CCh Byte 2 = 23h Byte 3 = Data1 Where: Data1 = bit 0 – GO0, bit 1 – GO1 Transceiver Response: Byte 1 = CCh Byte 2 = Data1 Where: Data1 = Data1 from Host command
AC4490/AC4486 Specifications 11/07/03 29 4.4.19 Write DAC The Host issues this command to write DA Out to a particular voltage. NOTE: DA Out is an unbuffered, high impedance output and must be buffered by the OEM Host when used. The transceiver uses a PWM (Pulse Width Modulator) to generate the analog voltage. The theory behind PWM is that a binary pulse is generated with a fixed duty cycle and rate. As such, this pin toggles between High and Low. This signal is filtered via an onboard R-C circuit and an analog voltage is generated. Duty Cycle specifies the ratio of time in one cycle that the pulse spends High proportionate to the amount of time it spends Low. So, with a duty cycle of 50% (80h), the pulse is High 50% of the time and Low 50% of the time; therefore the analog voltage would be half of 3.3V or 1.15V. A broad filter has been implemented on the transceiver and there is no advantage to using a slower update period. Generally, a faster update period is preferred. Host Command: Byte 1 = CCh Byte 2 = 24h Byte 3 = Data1 Byte 4 = Data2 Where: Data1 = Update Period where: TUpdate = (255 * (Data1 + 1)) / 14.7256+06 Data2 = Duty Cycle where: Vout = (Data2 / FFh) * 3.3V Transceiver Response: Byte 1 = CCh Byte 2 = Data1 Byte 3 = Data2 Where: Data1 = Data1 from Host Command Data2 = Data2 from Host Command 4.4.20 Set Max Power The Host Issues this command to limit the maximum transmit power emitted by the transceiver. This can be useful to minimize current consumption and satisfy certain regulatory requirements. Host Command: Byte 1 = CCh Byte 2 = 25h Byte 3 = Data1 Where: Data1 = New Max Power Transceiver Response: Byte 1 = CCh Byte 2 = Data1 Where: Data1 = Data1 from Host Command
AC4490/AC4486 Specifications 11/07/03 30 4.4.21 Transmit Buffer Empty The Host issues this command to determine when the RF Transmit buffer is empty. The Host will not receive the transceiver response until that time. Host Command: Byte 1 = CCh Byte 2 = 30h Transceiver Response: Byte 1 = CCh Byte 2 = 00h 4.4.22 Disable Sync to Channel The Host issues this command to disable Sync to Channel mode. Host Command: Byte 1 = CCh Byte 2 = 85h Transceiver Response: Byte 1 = CCh Byte 2 = RF Channel Number 4.4.23 Deep Sleep Mode The Host issues this command to put the transceiver into Deep Sleep mode. Once in Deep Sleep, the transceiver disables all RF communications and will not respond to any further commands until being reset or power cycled. This command is valid for both Servers and Clients. Host Command: Byte 1 = CCh Byte 2 = 86h Transceiver Response: Byte 1 = CCh Byte 2 = RF Channel Number 4.4.24 Reset Command The Host issues this command to perform a soft reset of the transceiver. Any transceiver settings modified by CC Commands will be overwritten by values stored in the EEPROM. Host Command: Byte 1 = CCh Byte 2 = FFh Transceiver Response: There is no response from the transceiver
AC4490/AC4486 Specifications 11/07/03 31 5. Theory of Operation 5.1 HARDWARE INTERFACE Below is a description of all hardware pins used to control the AC4490. 5.1.1 GIn (Generic Inputs 0 and 1) (pins 4 and 14 respectively) and GOn (Generic Outputs 0 and 1) (pins 1 and 9 respectively) Both GIn pins serve as generic input pins. Both GOn pins serve as generic output pins. Reading and writing of these pins can be performed using CC Commands (details can be found in the On-the-Fly Control Command Reference). These pins alternately serve as control pins when Modem Mode is enabled in the EEPROM. 5.1.2 TXD (Transmit Data) and RXD (Receive Data) (pins 2 and 3 respectively) Serial TTL The AC4490/AC4486 accepts 3.3 or 5VDC TTL level asynchronous serial data (the 500mW radio ONLY accepts 3.3V level signals) on the RXD pin and interprets that data as either Command Data or Transmit Data. Data is sent from the transceiver to the OEM Host via the TXD pin. RS-485 When equipped with an onboard RS-485 interface chip, TXD and RXD become the half duplex RS-485 pins. In this mode, the transceiver will be in listen mode except when it has data to send to the OEM host. TXD is the noninverted representation of the data and RXD is a mirror image of TXD. The transceiver will still use RTS (if enabled) in this mode. 5.1.3 Hop Frame (pin 6) The AC4490 is a frequency hopping spread spectrum radio. Frequency hopping allows the system to hop around interference in order to provide a better wireless link. Hop Frame transitions logic Low at the start of a hop and transitions logic High at the completion of a hop. The OEM Host is not required to monitor Hop Frame. The AC4486 is a single frequency radio, though it still generates a Hop Frame signal every time it transmits a timing beacon.
AC4490/AC4486 Specifications 11/07/03 32 5.1.4 CTS Handshaking (pin 7) The AC4490/AC4486 has an interface buffer size of 256 bytes. If the buffer fills up and more bytes are sent to the transceiver before the buffer can be emptied, data loss will occur. The transceiver prevents this loss by asserting CTS High as the buffer fills up and taking CTS Low as the buffer is emptied. CTS On in conjunction with CTS On Hysteresis control the operation of CTS. CTS On specifies the amount of bytes that must be in the buffer for CTS to be disabled (High). Even while CTS is disabled, the OEM Host can still send data to the transceiver, but it should do so carefully. Once CTS is disabled, it will remain disabled until the buffer is reduced to the size specified by CTS On Hysteresis. 5.1.5 RTS Handshaking (pin 8) With RTS Mode disabled, the transceiver will send any received packet to the OEM Host as soon as the packet is received. However, some OEM Hosts are not able to accept data from the transceiver all of the time. With RTS Mode Enabled, the OEM Host can keep the transceiver from sending it a packet by disabling RTS (logic High). Once RTS is enabled (logic Low), the transceiver can send packets to the OEM Host as they are received. Note: Leaving RTS disabled for too long can cause data loss once the transceiver’s receive buffer fills up. 5.1.6 9600 Baud (pin 12) 9600_BAUD – When pulled logic Low before applying power or resetting, the transceiver’s serial interface is forced to a 9600, 8-N-1 (8 data bits, No parity, 1 stop bit) rate. To exit, the transceiver must be reset or power-cycled with 9600_Baud logic High. This pin is used to recover transceivers from unknown baud rates only. It should not be used in normal operation. Instead the transceiver Interface Baud Rate should be programmed to 9600 baud if that rate is desired for normal operation. 5.1.7 RSSI (pin 13) Instantaneous RSSI Received Signal Strength Indicator is used by the Host as an indication of instantaneous signal strength at the receiver. The Host must calibrate RSSI without a RF signal being presented to the receiver. Calibration is accomplished by following the steps listed below to find a minimum and maximum voltage value. 1) Power up only one Client (no Server) transceiver in the coverage area. 2) Measure the RSSI signal to obtain the minimum value with no other signal present. 3) Power up a Server. Make sure the two transceivers are in close proximity and measure the Client’s peak RSSI once the Client reports In Range to obtain a maximum value at full signal strength.
AC4490/AC4486 Specifications 11/07/03 33 Validated RSSI As RSSI values are only valid when the local radio is receiving a RF packet from a remote radio, instantaneous RSSI can be very tricky to use. Therefore, the transceiver stores the most recent valid RSSI value. The Host issues the Report Last Good RSSI command to request that value (details can be found in the On-the-Fly Control Command Reference). Validated RSSI is not available at the RSSI pin. Figure 1 – RSSI Voltage vs. Received Signal Strength 5.1.8 UP_Reset (pin 15) UP_Reset provides a direct connection to the reset pin on the AC4490/AC4486 microprocessor and is used to force a soft reset. To guarantee a valid power-up reset, this pin should never be tied Low on power-up. For a valid power-on reset, reset must be High for a minimum of 10ms. 5.1.9 Command/Data (pin 17) When logic High, the transceiver interprets incoming Host data as transmit data to be sent to other transceivers and their Hosts. When logic Low, the transceiver interprets Host data as command data (see section 4). 00.20.40.60.811.2-105 -100 -95 -90 -85 -80 -75 -70 -65 -60 -55 -50Signal at Receiver (dBm)Voltage (VDC)
AC4490/AC4486 Specifications 11/07/03 34 5.1.10 AD In and DA Out (pins 18 and 19 respectively) AD In and DA Out can be used as a cost savings to replace Analog-to-Digital and Digital-to-Analog converter hardware. Reading and writing of these two pins locally can be performed using commands found in the On-the-Fly Control Command Reference. Note: DA Out is an unbuffered, high impedance output and must be buffered by the OEM Host when used. 5.1.11 In Range (pin 20) The IN_RANGE pin at the connector will be driven logic Low when a Client is in range of a Server on the same RF Channel and System ID. If a Client cannot hear a Server for the amount of time specified by Range Refresh, it will drive the IN_RANGE pin logic High and enter a search mode looking for a Server. As soon as it detects a Server, the IN_RANGE pin will be driven logic Low. A Server Host can determine which Clients are in range by the Server’s Host software polling a Client’s Host. IN_RANGE will always be Low on the Server.
AC4490/AC4486 Specifications 11/07/03 35 5.2 SOFTWARE PARAMETERS Following is a description of all software parameters used to control the AC4490. 5.2.1 RF Architecture (Unicast/Broadcast) The Server controls the system timing by sending out regular beacons (transparent to the transceiver Host) which contain system timing information. This timing information synchronizes the Client radios to the Server. Each network should consist of only one Server. There should never be two Servers on the same RF Channel Number in the same coverage area as the interference between the two Servers will severely hinder RF communications. The AC4490/AC4486 runs a Peer-to-Peer type architecture where all transceivers, whether Servers or Clients, can communicate with all other transceivers. To prohibit transceivers from receiving broadcast packets, Unicast Only can be enabled. 5.2.2 RF Mode All radios located on the same network must use the same RF Mode. RF Delivery Overview All packets are sent out over the RF as either addressed or broadcast packets. Addressed packets are only received by the radio specified by Destination Address. If addressed packets are desired, the Destination Address should be programmed with the MAC ID of the destination radio. To simplify EEPROM programming, Auto Destination can be enabled in Clients which allows the Client to automatically set its Destination Address to the address of the Server. Broadcast packets are sent out to every eligible transceiver on the network. If broadcast packets are desired, RF Delivery should be set to Broadcast. Acknowledge Mode In Addressed Acknowledge Mode, the RF packet is sent out to the receiver designated by the Destination Address. Transmit Retries is used to increase the odds of successful delivery to the intended receiver. Transparent to the OEM Host, the sending transceiver will send the RF packet to the intended receiver. If the receiver receives the packet free of errors, it will tell the sender. If the sender does not receive this acknowledge, it will assume the packet was never received and retry the packet. This will go on until the packet is successfully received or the transmitter exhausts all of its retries. The received packet will only be sent to the OEM Host if and when it is received free of errors. In Broadcast Acknowledge Mode, the RF packet is broadcast out to all eligible receivers on the network. Broadcast Attempts is used to increase the odds of successful delivery to the intended receiver(s). Transparent to the OEM Host, the sending transceiver will send the RF packet to the intended receiver. If the receiver detects a packet error, it will throw out the packet. This will go on until the packet is successfully received or the transmitter exhausts all of its attempts. Once the receiver successfully receives the packet it will send the packet to the OEM Host. It will throw out any duplicates caused by further Broadcast Attempts. The received packet will only be sent to the OEM Host if it is received free of errors.
AC4490/AC4486 Specifications 11/07/03 36 Stream Mode In Broadcast Stream mode, the RF packet is broadcast out to all eligible receivers on the network. In Addressed Stream Mode, the RF packet is sent out to the receiver designated by the Destination Address. The sending transceiver will send each RF packet out once. There are no retries on the packet. Whether or not the packet contains errors, the receiver(s) will send the packet to the OEM Host. In fact, if only part of the packet is able to be received, the transceiver will still send the partial packet to the OEM Host. Note: Stream Mode is incompatible with Full Duplex Mode. 5.2.3 Sub Hop Adjust Sub Hop Adjust is an AC4490/AC4486 protocol parameter and should only be modified at the recommendation of Aerocomm. 5.2.4 Duplex Mode In Half Duplex mode, the AC4490/AC4486 will send a packet out over the RF when it can. This can cause packets sent at the same time by a Server and a Client to collide with each other over the RF. To prevent this, Full Duplex Mode can be enabled. This mode restricts Clients to transmitting on odd numbered frequency “bins” and the Server to transmitting on even frequency bins. Though the RF hardware is still technically half duplex, it makes the radio seem full duplex. This can cause overall throughputs to be cut in half. Note: All transceivers on the same network must have the same setting for Full Duplex. Full Duplex mode is incompatible with Stream RF mode. 5.2.5 Interface Timeout/RF Packet Size Interface Timeout, in conjunction with RF Packet Size, determines when a buffer of data will be sent out over the RF as a complete RF packet based on whichever condition occurs first. Interface Timeout – Interface Timeout specifies a maximum byte gap between consecutive bytes. When that byte gap is exceeded, the bytes in the transmit buffer are sent out over the RF as a complete packet. Interface timeout is adjustable in 1ms increments and has a tolerance of ?1ms. Therefore, the Interface Timeout should be set to a minimum of 2. The default value for Interface Timeout is 4 or 4ms. RF Packet Size – When the amount of bytes in the transceiver transmit buffer equals RF Packet Size, those bytes are sent out as a complete RF packet. Every packet the transceiver sends over the RF contains extra header bytes not counted in the RF Packet Size. Therefore, it is much more efficient to send a few large packets than to send many short packets. However, if RF Packet size is set too large and Acknowledge Mode is enabled, the transceiver will not be able to send any packets because Acknowledge Mode requires the entire RF packet to be sent in the same hop whereas Stream Mode packets can span multiple hops.
AC4490/AC4486 Specifications 11/07/03 37 5.2.6 Serial Interface Baud Rate This two-byte value determines the baud rate used for communicating over the serial interface to a transceiver. Table 8 - Baud Rate/Timeout lists values for some common baud rates. Baud rates below 1200 baud are not supported. For a baud rate to be valid, the calculated baud rate must be within ?3% of the OEM Host baud rate. If the 9600_BAUD pin (Pin 12) is pulled logic Low at reset, the baud rate will be forced to 9,600. For Baud Rate values other than those shown in Table 5 - Baud Rate, the following equation can be used: BAUD = 100h - (14.7456E+06 / (64 * desired baud rate)) BaudH= Always 0 BaudL = Low 8 bits of BAUD (base16) Table 9 – Baud Rate/Interface Timeout Baud Rate BaudL (42h) BaudH (43h) Minimum Interface Timeout (58h) 115,200 FEh 00h 02h 57,600 FCh 00h 02h 38,400 FAh 00h 02h 28,800 F8h 00h 02h 19,200 F4h 00h 02h 14,400 F0h 00h 03h 9,600 E8h 00h 03h 4800 D0h 00h 05h 2400 A0h 00h 09h 1200 40h 00h 11h 5.2.7 Network Topology RF Channel Number – RF Channel Number provides a physical separation between collocated networks. The AC4490 is a spread spectrum frequency hopping radio with a fixed hopping sequence. Without synchronizing the different networks to each other, collocated systems on different channel numbers can interfere with each other. To avoid this kind of interference, collocated networks can use Sync-to-Channel. A Server radio with Sync-to-Channel enabled must have its Sync Channel set to another Server’s RF Channel Number. It is required that a Server with Sync-to-Channel enabled must have its Sync Channel set to a value less than its RF Channel Number. Collocated networks must use the same Channel Set. See the Diagrams below:
AC4490/AC4486 Specifications 11/07/03 38 Daisy-Chain Network Configuration Centralized Network Configuration Frequency Offset – Frequency Offset is an AC4490/AC4486 protocol parameter used in conjunction with RF Channel Number. Table 10 – US and International RF Channel Number Settings
AC4490/AC4486 Specifications 11/07/03 39 Channel Set RF Channel Number Range (40h) Frequency Details and Regulatory Requirements Countries Frequency Offset (46h) 0 (AC4490) 0 – 0Fh 902 – 928MHz (26 hop bins) US/Canada 1 1 (AC4490) 10 – 2Fh 902 – 928MHz (50 hop bins) US/Canada N/A 2 (AC4490) 30 – 37h 915 – 928MHz Australia 0 3 (AC4486) 38h 869.4 – 869.65MHz (Up to 500mW at 10% maximum transmit vs. receive duty cycle) Europe 0 4 (AC4486) 39h 869.7 – 870MHz (Up to 5mW with no duty cycle requirement) Europe 0 System ID – System ID is similar to a password character or network number and makes network eavesdropping more difficult. A receiving radio will not go in range of or communicate with another radio on a different System ID. 5.2.8 Auto Config The AC4490/AC4486 has several variables that control its RF performance and vary by RF Mode and RF Architecture. Enabling Auto Config will bypass the value for these variables stored in EEPROM and use predetermined values for the given mode. Below is a list containing all of the variables affected by Auto Config and their respective values (values are all in hexadecimal format). When Auto Config is disabled, these values must be programmed in the radio EEPROM for the corresponding mode of operation.
AC4490/AC4486 Specifications 11/07/03 40 Table 11 – Auto Config Parameters Acknowledge Mode Parameter (those not named are undocumented protocol parameters) EEPROM Address Default Stream Mode One Beacon Mode Disabled One Beacon Mode Enabled Sub Hop Adjust 36 66 A0 A0 A0 47 0E 0E 0E 0E 48 90 90 90 90 4E 09 08 09 09 53 80 N/A3 80 80 54 07 07 07 07 RF Packet Size 5B 46 90 50 68 CTS On 5C D2 C0 DC DC CTS On Hysteresis 5D AC BE B0 B0 5E 23 10 23 23 5F 08 08 08 08 5.2.9 One Beacon Mode The beacon, which is sent by the Server and contains system timing information, takes approximately 1ms to send. Due to the protocol built into the AC4490, the transceiver can maintain perfect synchronization even if it only hears a beacon once every two minutes. Normally the Server will send a beacon once every hop. Enabling One Beacon mode causes the beacon to only be sent once per complete hop cycle. Using this feature can make initial synchronization take slightly longer and can make communications more difficult if operating on the fringe but can increase net throughput. Range Refresh – The Server sends out timing beacons at regular intervals to maintain Client synchronization. Upon hearing a beacon, a Client will be in range of the Server and will assert its IN_RANGE pin Low. Each time the Client hears a Server beacon, it resets the Range Refresh timer. If the timer ever expires the Client will be out of range, will take the IN_RANGE pin High and will enter acquisition mode trying to find the Server again. Therefore, Range Refresh specifies the maximum amount of time a Client can go without hearing a Server beacon. This variable is particularly useful when operating on fringe coverage areas. The Range Refresh timer is equal to 320ms * the value of Range Refresh. When One Beacon mode is enabled, it is recommended that Range Refresh be increased from its default setting (testing might be required to determine the appropriate setting). 3 N/A: This parameter is not affected by Auto Config and the EEPROM value is used instead.
AC4490/AC4486 Specifications 11/07/03 41 5.2.10 Max Power Max Power provides a means for controlling the RF transmit output power of the AC4490/AC4486. The following table lists some common values for Max Power and their current consumption. Output power and current consumption can vary by as much as ?10% per radio. Transmit power is shown here in dBm (decibels per meter) and mW (milliwatts). The equations for converting between the two are shown below: Power (dBm) = 10 log10 Power (mW) Power (mW) = 10^(Power (dBm) / 10) able 12 – Max Power Settings for 100mW Transmitter Max Power (Address 63h) 100% Transmit Current (mA) Transmit Power Output(dBm) Transmit Power Output (mW) 00h 47 -20 0.01 01h 50 -10 0.1 02h 50.5 -3 0.5 03h 52 1 1.26 04h 55 4 2.51 05h 58.5 7 5.01 06h 63.5 9 7.94 07h 69 10.5 11.22 08h 76 12 15.85 09h 83 13.5 22.39 0Ah 90.5 14.5 28.18 0Bh 97.5 15.5 35.48 0Ch 105 16.5 44.67 0Dh 111.5 17 50.12 0Eh 118 17.5 56.23 0Fh 123.5 18 63.1 1Eh 140.5 19 79.43 60h 156 20 100 Table 13 – Max Power Settings for 1000mW Transmitter Max Power (Address 63h) 100% Transmit Current (mA) Transmit Power Output(dBm) Transmit Power Output (mW) 00h 310 -4.5 0.35 01h 320 6 3.98 02h 335 11.5 14.13 03h 345 14.5 28.18 04h 365 16.5 44.67 05h 395 18 63.1
AC4490/AC4486 Specifications 11/07/03 42 06h 440 19.5 89.13 07h 485 20.5 112.2 08h 525 22.5 177.83 09h 580 23.5 223.87 0Ah 620 24 251.19 0Bh 665 24.5 281.84 0Ch 695 25 316.23 0Dh 745 25.5 354.81 0Eh 810 26 398.11 0Fh 850 26.5 446.68 1Eh 880 27 501.19 60h 985 29.5 891.25 5.2.11 Interface Options Modem Mode – Full modem handshaking is supported by the transceivers when enabled in EEPROM. Modem Mode is incompatible with RS-485 DE mode. Because Command/Data performs an alternate function when this mode is enabled, CC on-the-fly commands cannot be used and the only way to enter Configuration Mode is by forcing 9600 baud through the 9600_BAUD pin. Therefore, modem mode, though enabled in EEPROM, will be ignored when 9600 baud is forced. Both interfaces are shown below.
AC4490/AC4486 Specifications 11/07/03 43 Table 14 – Transceiver Interface to DCE (Server Radio) When Interfacing the AC4490/AC4486 to a DCE (Data Communications Equipment): DCE Pin Number DCE Pin Name Direction with Respect to Radio AC4490/AC4486 Pin Name AC4490/AC4486 Pin Number 1 DCD In GI1 14 2 RXD In RXD 3 3 TXD Out TXD 2 4 DTR Out GO0 1 5 GND 5 6 DSR In Command/Data 17 7 RTS Out CTS 7 8 CTS In RTS 8 9 RI In GI0 4 Table 15 – Transceiver Interface to DTE (Client Radio) When Interfacing the AC4490/AC4486 to a DTE (Data Terminal Equipment): DTE Pin Number DTE Pin Name Direction with Respect to Radio AC4490/AC4486 Pin Name AC4490/AC4486 Pin Number 1 DCD Out GO0 1 2 RXD Out TXD 2 3 TXD In RXD 3 4 DTR In GI0 4 5 GND 5 6 DSR Out Hop Frame 6 7 RTS In RTS 8 8 CTS Out CTS 7 9 RI Out GO1 9 RS-485 DE Control – When enabled in EEPROM, the transceiver will use the GO0 pin to control the DE pin on external RS-485 circuitry. If enabled, when the transceiver has data to send to the host, it will assert GO0 Low, send the data to the host, and take GO0 High.
AC4490/AC4486 Specifications 11/07/03 44 6. Dimensions Critical parameters are as follows: Interface Connector – 20 pin OEM interface connector (Samtec TMM-110-01-L-D-SM, mates with Samtec SMM-110-02-S-D) MMCX Jack – Antenna connector (Telegartner P/N J01341C0081) mates with any manufacturer’s MMCX plug Figure 2 - AC4490/AC4486 (with MMCX Connector) Mechanical

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