V E R S I O N 3.
Contents AC4490 TRANSCEIVER MODULE 1 AC4490 features 1 Overview 1 SPECIFICATIONS 3 Pin Definitions 4 Electrical Specifications 6 THEORY OF OPERATION 7 RF Architecture 7 Modes of Operation 7 Transmit Mode 7 Receive Mode 7 Command Mode 8 API CONTROL 8 Receive API Packet 9 API Transmit Packet 9 API Send Data Complete 9 API Receive Packet 9 Protocol Status/Receive Acknowledgement 10 Protocol Status 10 Receive Acknowledgement 10 Long Range Mode 10 SERIAL INTERFACE 12 Serial Communications 12 Asynchronous Oper
Contents Enhanced Receive API 55 Normal Receive Mode (non-API) 55 Loopback Repeater 55 Time Division Multiple Access Network 56 APPENDIX IV - SYNC TO CHANNEL 57 Sync to Channel 57 What is it and do I need it? 57 How do I configure Sync to Channel? 59 I've configured my radios, what's next? 65
DOCUMENT INFORMATION Copyright © 2007 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.
DOCUMENT INFORMATION Revision Description Version 1.0 3/15/02 - Initial Release Version Version 1.1 12/18/02 - Preliminary Release Version 1.2 12/20/02 - Preliminary Release. Changed location of new interface pins for higher compatibility with AC4424 family. Version 1.3 1/29/03 - Updated interface baud rate formula/table. Updated current consumption table. Corrected RSSI plot. Updated interface timeout information. Renamed product family to AC4490. Multiple EEPROM read/write now allowed.
DOCUMENT INFORMATION Revision Description Version 2.6 7/13/06 - Added AC4490LR-1000 documentation. Added Long Range documentation and EEPROM parameters. Removed Read/Write API Control Commands. Updated ordering information and product tree. Version 2.7 8/3/06 - Added Table of Contents. Version 2.8 10/16/06 - Updated Approved Antenna List. Version 2.9 1/9/07 - Updated Approved Antenna List. Updated Agency Identification numbers. Version 3.
AC4490 T RANSCEIVER M ODULE 1 The compact AC4490 900MHz transceiver can replace miles of cable in harsh industrial environments. Using field-proven FHSS technology which needs no additional FCC licensing in the Americas, OEMs can easily make existing systems wireless with little or no RF expertise. AC4490 FEATURES NETWORKING AND SECURITY • • • • • • • • • Drop-in replacement for AC4424 2.
2 A C 4 4 9 0 TR A N S C E I V E R M O D U L E This document contains information about the hardware and software interface between an AeroComm AC4490 transceiver and an OEM Host. Information includes the theory of operation, specifications, interface definition, configuration information and mechanical drawings. The OEM is responsible for ensuring the final product meets all appropriate regulatory agency requirements listed herein before selling any product.
2 S PECIFICATIONS Table 1: AC4490 Specifications General 20 Pin Interface Connector Molex 87759-0030, mates with Samtec SMM-110-02-S-D RF Connector Johnson Components 135-3711-822 Antenna AC4490-1x1: Customer must provide AC4490-200: MMCX Connector or integral antenna AC4490-1000: MMCX Connector Serial Interface Data Rate Baud rates from 1200 bps to 115,200 bps Power Consumption (typical) 1x1: 200: 1000: 10%TX 33mA 38mA 130mA Duty Cycle (TX=Transmit; RX=Receive) 50%TX 100%TX 100%RX Pwr-Down Deep
4 SPECIFICATIONS Table 1: AC4490 Specifications Transceiver (Cont’d) Range, Line of Site (based on 3dBi gain antenna) AC4490-1x1: AC4490-200: AC4490LR-200: AC4490-1000: AC4490LR-1000: Up to 1 mile Up to 4 miles Up to 8 miles Up to 20 miles Up to 40 miles Environmental Temperature (Operating) -40°C to 80°C Temperature (Storage) -50°C to +85°C Humidity (non-condensing) 10% to 90% Physical Dimensions Transceiver with MMCX Connector: 1.65” x 1.9” x 0.20” Transceiver with Integral Antenna: 1.65” x 2.
SPECIFICATIONS Table 2: AC4490 Pin Definitions Module Pin 1x1 Pin 4 52 5 3 6 Type Signal Name GI0 GND GND O Hop Frame Function Generic Input pin Signal Ground Pulses low when the transceiver is hopping frequencies. 7 9 O CTS Clear to Send – Active Low when the transceiver is ready to accept data for transmission. 8 102 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.
6 SPECIFICATIONS ELECTRICAL SPECIFICATIONS Table 3: Input Voltage Characteristics AC44901x1 / AC4490-1000M AC4490-200X High Min. High Max. Low Min. Low Max. High Min. High Max. Low Min. Low Max. Unit RS485A/B N/A 12 -7 N/A N/A 12 -7 N/A V RXD 2.31 3.3 0 0.99 2 5.5 0 0.8 V GI0 2.31 3.3 0 0.99 2 5.5 0 0.8 V RTS 2.31 3.3 0 0.99 2 5.5 0 0.8 V Test 2.31 3.3 0 0.99 2 5.5 0 0.8 V GI1 2.31 3.3 0 0.99 2 5.5 0 0.8 V UP_RESET 0.8 3.3 0 0.
T HEORY OF O PERATION 3 RF ARCHITECTURE The AC4490 utilizes a Server-Client network where all Clients synchronize their hopping to the Server. The Server transmits a beacon during the first 1 ms of every hop (20 ms). The Client transceivers listen for this beacon and upon hearing it assert their In_Range Low and synchronize their hopping with the Server.
8 THEORY OF OPERATION Command Mode A radio will enter Command Mode when data is received over the serial interface from the OEM Host and either the Command/Data pin (pin 17) is logic Low or the received data contains the “AT+++” (Enter AT Command Mode) command. Once in Command Mode, all data received by the radio is interpreted as command data. Command Data can be either EEPROM Configuration or On-The-Fly commands.
THEORY OF OPERATION specifying various vital parameters used to control radio settings and packet routing on a packet-by-packet basis. The API features can be used in any combination that suits the OEM’s specific needs. Receive API Packet Implemented in v6.3 of the firmware and later. Receive API Packet can be enabled to determine the sender of a message. This causes the radio to append a header to the received packet detailing the length of the data packet and the sender’s MAC address.
10 THEORY OF OPERATION include the MAC address of the source radio as well as an RSSI indicator which can be used to determine the link quality between the two. API Receive Packet is enabled when bit-0 of the Enhanced API Control byte is enabled.
THEORY OF OPERATION Note: Long Range Mode is only available on the AC4490LR-200 and AC4490LR-1000 transceivers with the following board revisions and firmware v6.7+. Table 5: Long Range Requirements Module Board Number Board Revision AC4490LR-200 0050-00100 Rev. 1 and higher AC4490LR-1000 0050-00102 Rev. 1 and higher www.aerocomm.
S ERIAL I NTERFACE 4 In order for the OEM Host and a transceiver to communicate over the serial interface they need to have the same serial data rate. Refer to the following sections to ensure that the OEM Host data rate matches the serial interface baud rate. SERIAL COMMUNICATIONS The AC4490 is a TTL device which can be interfaced to a compatible UART (microcontroller) or level translator to allow connection to serial devices.
SERIAL INTERFACE Figure 3: Even Parity Bit Note: Enabling parity cuts throughput and the interface buffer in half. OEM HOST DATA RATE The OEM Host Data Rate is the rate with which the OEM Host and transceiver communicate over the serial interface. This rate is independent of the RF baud rate, which is fixed at 76.8 kbps. Possible values range from 1200 bps to 115,200 bps. Note: Enabling Parity cuts throughput in half and the Interface Buffer size in half.
14 SERIAL INTERFACE 6 14.
SERIAL INTERFACE FLOW CONTROL Flow control refers to the control of data flow between transceivers. It is the method used to handle data in the transmit/receive buffer and determines how data flow between the transceivers is started and stopped. Often, one transceiver is capable of sending data much faster than the other can receive and flow control allows the slower device to tell the faster device when to pause and resume data transmission.
16 SERIAL INTERFACE should be a strong consideration when designing the system. ENGINEER’S TIP In High-density applications, what amount of latency should be expected? It is not easy to predict the exact amount of latency in high-density applications. There are many variables that affect system latency. The three variables that most affect the latency are the network load, the distance between transceivers, and whether the transceivers are operating in a broadcast or addressed mode.
5 S OFTWARE I NTERFACE NETWORKING System ID - System ID (EEPROM address 0x76) is similar to a password character or network number and makes network eavesdropping more difficult. A transceiver will not establish a Session or communicate with a transceiver operating on a different System ID or Channel Number. RF Channel Number - Channels 0x00 - 0x0F and 0x30 - 0x37 hop on 26 different frequencies. Channels 0x10 - 0x2F use 50 different frequencies.
18 SOFTWARE INTERFACE will be asserted), before establishing communications. Server B will not be affected and can communicate with its Clients. Refer to the Sync-to-Channel Appendix for further details and sample configuration. ONE BEACON MODE / RANGE REFRESH One Beacon - The 4490 maintains synchronization by using the timing information in the Server’s beacon.
SOFTWARE INTERFACE Table 11: Auto Config Parameters EEPROM Address Default One Beacon Mode Disabled One Beacon Mode Enabled 0x4E 0x09 0x09 0x09 0x53 0x80 0x80 0x80 0x54 0x07 0x07 0x07 RF Packet Size 0x5B 0x46 0x50 0x68 CTS On 0x5C 0xD2 0xDC 0xDC CTS Off 0x5D 0xAC 0xB0 0xB0 0x5E 0x23 0x23 0x23 0x5F 0x08 0x08 0x08 Parameter INTERFACE OPTIONS Modem Mode Full modem handshaking is supported by the AC4490 when enabled in EEPROM. Modem mode is incompatible with RS-485 DE.
20 SOFTWARE INTERFACE Table 13: Transceiver Interface to DTE (Client) DTE Pin Number DTE Pin Name Direction with respect to transceiver AC4490 Pin Name AC4490 Pin Number 1 DCD Out GO0 1 2 RXD Out TXD 2 3 TXD In RXD 3 4 DTR In GI0 4 5 GND - GND 5 6 DSR Out Hop Frame 6 7 RTS In RTS 7 8 CTS Out CTS 8 9 RI Out G01 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.
T IMING D IAGRAMS AC4490 TIMING DIAGRAMS Figure 4: Addressed Mode with Timeout Figure 5: Addressed Mode with Fixed Packet Length www.aerocomm.
22 TIMING DIAGRAMS Figure 6: Broadcast Mode with Timeout Figure 7: Broadcast Mode with Fixed Packet Length
H ARDWARE I NTERFACE 7 Below is a description of all hardware pins used to control the AC4490. PIN DEFINITIONS Generic I/O Both GIn pins serve as generic input pins and both GOn pins server as generic output pins. Reading and writing of these pins can be performed using CC Commands. These pins alternatively serve as control pins when modem mode is enabled. TXD & RXD SERIAL TTL The AC4490-200 accepts 3.
24 HARDWARE INTERFACE prevent the transceiver from sending it data 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 256 byte receive buffer fills up. Test / 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).
HARDWARE INTERFACE Figure 8: RSSI Voltage vs. Received Signal Strength 1.2 1 Voltage (VDC) 0.8 0.6 0.4 0.2 0 -105 -100 -95 -90 -85 -80 -75 -70 -65 -60 -55 -50 Signal at Re ce iv e r (dBm) UP_Reset UP_Reset provides a direct connection to the reset pin on the AC4490 microprocessor and is used to force a soft reset. Command/Data When logic High, the transceiver interprets incoming OEM Host data as transmit data to be sent to other transceivers and their OEM Hosts.
8 C ONFIGURING THE AC4490 The AC4490 can be configured using the CC Configuration Commands. The CC Commands can be issued using either Hardware or Software Configuration. To use Hardware Configuration, pin 17 of a transceiver must be asserted Low. Software Configuration can be used by entering AT Command Mode before issuing the CC Commands.
CONFIGURING THE AC4490 AT COMMANDS The AT Command mode implemented in the AC4490 creates a virtual version of the Command/Data pin. The “Enter AT Command Mode” Command asserts this virtual pin Low (to signify Command Mode) and the “Exit AT Command Mode” Command asserts this virtual pin High (to signify Data). Once this pin has been asserted Low, all On-the-Fly CC Commands documented in the manual are supported.
28 CONFIGURING THE AC4490 Table 14: Command Quick Reference Command Name Command (All Bytes in Hex) Return (All Bytes in Hex) AT Enter CommandMode 0x41 0x54 0x2B 0x2B 0x2B 0x0D 0xCC 0x43 0x4F 0x4D Exit AT CommandMode 0xCC 0x41 0x54 0x4F 0x0D - 0xCC 0x44 0x41 0x54 Status Request 0xCC 0x00 0x00 - - - 0xCC Firmware Version Change Channel 0xCC 0x02 New Channel - - 0xCC Change Server/Client 0xCC 0x03 - - 0xCC Firmware Version Change Sync Channel 0xCC 0x05 New
CONFIGURING THE AC4490 Table 14: Command Quick Reference Command Name Command (All Bytes in Hex) Return (All Bytes in Hex) Set Max Power 0xCC 0x25 New Max Power Report Last Packet RSSI 0xCC 0x26 Long Range Mode1 0xCC 0x27 Transmit Buffer Empty 0xCC 0x30 - - - - 0xCC 0x00 - - Disable Sync to Channel 0xCC 0x85 - - - - 0xCC Channel - - Deep Sleep Mode 0xCC 0x86 - - - - 0xCC Channel - - Enter Probe 0xCC 0x8E - 0xCC 0x00 or 0x01 - - Read Temperature 0xCC 0
30 CONFIGURING THE AC4490 COMMAND DESCRIPTIONS E n t e r AT C o m ma n d M o d e Prior to sending this command, the OEM Host must ensure that the transceiver’s RF transmit buffer is empty. If the buffer is not empty, the radio will interpret the command as data and it will be sent over the RF. This can be accomplished by waiting up to one second between the last packet and the AT command.
CONFIGURING THE AC4490 Sl ee p Wal k P o wer - Dow n After the Host issues this command, the transceiver will de-assert its In_Range line after entering power down. A Client in power down will remain in sync with a Server for a minimum of 2 minutes. To maintain syncronization with the Server, the Client should re-sync at least once every 2 minutes. This is done by sending the Power Down wake up command and waiting for the In_Range line to go active.
32 CONFIGURING THE AC4490 A ut o D es t i na t i o n The Host issues this command to change the Auto Destination & Auto Channel settings.
CONFIGURING THE AC4490 Table 15: Received Signal Strength Signal Strength (dBm) RSSI Value (Hex) Signal Strength (dBm) RSSI Value (Hex) -42 to -39 0x0C -76 0x71 -46 0x0D -79 0x78 -49 0x0E -82 0x84 -52 0x11 -86 0x9A -56 0x17 -89 0xAD -59 0x1C -92 0xBD W r i t e D i g it a l O u t p u t s The OEM Host issues this command to write both digital output lines to particular states.
34 CONFIGURING THE AC4490 T r a n sm i t B u f f e r E m p t y The OEM Host issues this command to determine when the RF transmit buffer is empty. The Host will not receive the transceiver response until that time. Command: 0xCC 0x30 Number of Bytes Returned: 2 Response: 0xCC 0x00 D is ab l e S yn c - t o - Ch a n n el The OEM Host issues this command to disable Sync to Channel mode. This command is valid only for Servers.
CONFIGURING THE AC4490 EE PROM Byte Re ad Upon receiving this command, a transceiver will respond with the desired data from the addresses requested by the OEM Host. Command: 0xCC 0xC0
Number of Bytes Returned: 4+ Response: 0xCC EE PROM Byte W ri t e Upon receiving this command, a transceiver will write the data byte to the specified address but will not echo it back to the OEM Host until the EEPROM write cycle is complete (up to 10 ms).9 EEPROM P ARAMETERS The OEM Host can program various parameters that are stored in EEPROM which become active after a power-on reset. The table below gives the locations and descriptions of the parameters that can be read/written by the OEM Host. Factory default values are also shown. Do not write to any EEPROM addresses other than those listed below. Do not copy one transceiver’s EEPROM to another transceiver as doing so may cause the transceiver to malfunction.
EEPROM PARAMETERS Table 16: EEPROM Parameters Parameter Control 0 EEPROM Address Length (Bytes) 0x45 1 Range 0x00 0xFF - Default 0x14 Description Settings are: bit-7: One Beacon Mode 0 = Beacon every hop (disabled) 1 = Beacon once per hop cycle (enabled) bit-6: DES Enable 0 = Disable Encryption 1 = Enable Encryption bit-5: Sync to Channel 0 = Disabled 1 = Enabled bit-4: Aerocomm Use Only bit-3: Aerocomm Use Only bit-2: Aerocomm Use Only bit-1: RF Delivery 0 = Addressed packets 1 = Broadcast packets
38 EEPROM PARAMETERS Table 16: EEPROM Parameters EEPROM Address Length (Bytes) RF Packet Size 0x5B 1 0x01 0x80 - 0x80 Used in conjunction with Interface Timeout; specifies the maximum size of an RF packet. CTS On 0x5C 1 0x01 0xFF - 0xD2 CTS will be deasserted (High) when the transmit buffer contains at least this many characters.
EEPROM PARAMETERS Table 16: EEPROM Parameters Parameter Protocol Status Receive ACK / Receive API Enhanced Control API EEPROM Address Length (Bytes) 0xC0 1 0xE3, oxFF oxFF oxE3 = GO0 outputs the Protocol Status and GO1 outputs the Received Acknowledgement signal 0xFF = Disable Protocol Status / Receive ACK 0xC1 1 0xE3, 0xFF 0xFF 0xE3 = Enabled 0xFF = Disabled 0xC6 1 0xF8 Settings are: bit-7: Enhanced API Control Enable Range Default Description 0 = Enable Enhanced API Control 1 = Di
10 D IMENSIONS MECHANICAL DRAWINGS Interface Connector - 20 pin OEM Interface connector (Molex 87759-0030, mates with Samtec SMM-110-02-S-D MMCX Jack - Antenna Connector (Johnson Components 135-3711-822) Figure 10: AC4490 (with MMCX connector) Mechanical 2 0 p in h e a d e r , 0 .0 2 0 s q . p o s ts o n 0 .0 7 9 in c h (2 m m ) c e n te rs 0 .1 5 7 0 .1 8 0 0 .0 6 7 0 .0 6 2 0 .0 0 0 M M C X ja c k 0 .1 2 5 d ia n o n -p la te d h o le s (2 ) p la c e s 1 .6 5 0 0 .
DIMENSIONS Figure 11: AC4490 with integral gigaAnt Antenna (on bottom) Mechanical 20 pin header, 0.020 sq. posts on 0.079 inch (2mm) centers 0.180 0.086 0.000 -0.152 0.157 0.062 0.000 GigaAnt Snap-In Antenna 0.125 dia non-plated holes (4) places 1.650 1.650 1.550 pins 1 2 1.180 1.010 J1 0.100 0.000 www.aerocomm.com 2.650 2.345 2.550 2.030 1.875 0.435 0.100 0.150 0.000 0.
DIMENSIONS DA_OUT DO1 IN_RANGE CMD/DATA UP_RESET AD_IN Module Outline DI1 Figure 12: AC4490-1x1 Mechanical 21 20 19 18 17 16 15 0. RESET 22 14 RF_PORT 9600_BAUD (TST_MODE) 23 13 GND (note 2) N/C 24 12 RSSI N/C 25 11 VCC (note 1) N/C 26 10 RTS N/C 27 9 CTS N/C 28 8 N/C 0. 0. cut corner indicates pin 1 1 2 3 4 5 6 7 HOP_FRAME VCC (note 1) GND DO0 DI0 TXD RXD 1 AC4490-1X1 RECOMMENDED PAD PATTERN (viewed from top) 0 005068004503 1.080 0.080 x 0.
DIMENSIONS Figure 13: AC4490-1x1 PCB Considerations www.aerocomm.
O RDERING I NFORMATION 11 PRODUCT PART NUMBER TREE DEVELOPER KIT PART NUMBERS All of the above part numbers can be ordered as a development kit by prefacing the part number with “SDK-”. As an example, part number AC4490-200A can be ordered as a development kit using the part number: SDK-AC4490-200A. All developer’s kits include (2) transceivers, (2) development boards, (2) 7.
12 C OMPLIANCY I NFORMATION AC4490-1X1 Due to the RF antenna trace residing on the OEM Host PCB, the FCC will not grant modular approval for the AC44901x1 and requires the OEM to submit their completed design for approval. Contact AeroComm for the approval procedure. AGENCY IDENTIFICATION NUMBERS Agency compliancy is a very important requirement for any product development.
46 COMPLIANCY INFORMATION Table 18: AC4490 Approved Antennas Gain (dBi) 2 0 0 A 2 0 0 M 2 0 0 L R 1 0 0 0 M 1/2 Wave Dipole 2 - X X X Nearson 1/2 Wave Dipole 2 - X X X S467AH-915 Nearson 1/2 Wave Dipole 2 - X X X 0600-00027 S467AH-915R Nearson 1/2 Wave Dipole 2 - X X X 0600-00028 S161AH-915R Nearson 1/2 Wave Dipole 2.5 - X X X 0600-00029 S161AH-915 Nearson 1/2 Wave Dipole 2.
COMPLIANCY INFORMATION OEM EQUIPMENT LABELING REQUIREMENTS WARNING: The OEM must ensure that FCC labeling requirements are met. This includes a clearly visible label on the outside of the OEM enclosure specifying the appropriate AeroComm FCC identifier for this product as well as the FCC notice below. The FCC identifiers are listed above.
I A PPENDIX I - S AMPLE P OWER S UPPLY Below is a simple switching power supply that provides enough current to easily power any Aerocomm OEM module. It utilizes low cost, off the shelf components that fit into a small area. This supply has an input voltage range of +6 volts to +18 volts and will output +3.4 volts at 1.5 amps. Included is a schematic, bill of materials with manufacture's name and part numbers and a sample PCB layout.
APPENDIX I - SAMPLE POWER SUPPLY SCHEMATIC PCB LAYOUT www.aerocomm.
50 APPENDIX I - SAMPLE POWER SUPPLY
II A PPENDIX II - 5V TO 3.3V L EVELS All inputs on the AC4490-200 & AC4490-1000 are weakly pulled high via 10 kohm resistors. The AC4490-200 has 5V inputs while the AC4490-1000 & AC4490-1x1 have 3.3V inputs. The AC4490-200 uses an octal buffer to drop the 5V to the required 3.3V level; the -1000 and -1x1 leave this to the OEM. Some of the most common voltage conversion methods are described below. VOLTAGE LEVEL CONVERSION IC’S This is the easiest and most efficient method.
III A PPENDIX III - API The API feature set of the AC4490 provides powerful packet routing capabilities to the OEM Host. The number of API configurations is endless as individual radios can all be configured differently to suit the OEM Host’s varying needs. Some of the most common implementations are described in the following pages. POLLING NETWORK Many applications require multiple locations to report back to a single access point.
APPENDIX III - API Addressed Transmit API 1 To poll radio 1, the SAP transmits the packet using the following format: 2 To poll radio 2, the SAP transmits the packet using the following format: 3 To poll radio 2, the SAP transmits the packet using the following format: 4 This continues until all radios have successfully been polled by the SAP. Broadcast Transmit API To send out a universal poll request or data packet, the OEM may wish to utilize the broadcast portion of the Transmit API command.
54 APPENDIX III - API The remote response is dependent on the OEM’s specific needs and equipment. In many cases, remote radios are connected to dumb devices without the intelligence to filter out or append specific portions of a packet that is transmitted or received. Since the 7 bytes of overhead in the Transmit API command are not sent over the RF, the remotes will receive only the payload data, “STATUS”.
APPENDIX III - API Enhanced Receive API When Enhanced Receive API is enabled, the transceiver will receive the reply data + the MAC address of the source radio and one RSSI value; RSSI* is how strong the local heard the remote transceiver. It may be useful to the OEM Host to determine which radio each packet originated from. When Enhanced Receive API is enabled, every packet received by the transceiver will be received in the above format.
56 APPENDIX III - API & C. If the repeater is set to Broadcast mode, radio A will receive a copy of each packet that it sends. If the repeater has a specific destination address (i.e. 12 34 A2), then radio A will not receive the packet as its MAC address will not match the specified destination address. TIME DIVISION MULTIPLE ACCESS NETWORK For a more intelligent network, a TDMA system can be implemented.
IV A PPENDIX IV - S YNC TO C HANNEL SYNC TO CHANNEL What is it and do I need it? AeroComm uses frequency hopping protocol with a fixed pseudo-random hopping sequence on our transceivers. This protocol yields superior interference rejection and multipath immunity. The Server radio sends timing beacons out on a regular interval and the Clients hear these beacons and synchronize their frequency hopping to the Server.
58 APPENDIX IV - SYNC TO CHANNEL What happens if you don't enable Sync-to-Channel and you have collocated Servers? You have good odds that you will see a decrease in throughput due to the systems trying to occupy the same frequency at the same time. In severe cases, you could lose communications all together depending on how much bandwidth your system requires. Due to crystal differences between the Servers, you could see the interference come and go.
APPENDIX IV - SYNC TO CHANNEL Figure 15: Servers with Sync-to-Channel Enabled How do I configure Sync to Channel? To configure sync to channel, you must use our OEM configuration software. This can be downloaded from our website http://www.aerocomm.com by clicking the software link at the top of the screen and selecting the Developer Kit Software. You will be prompted to install the software on your PC.
60 APPENDIX IV - SYNC TO CHANNEL Figure 16: PC Settings Page 5. Go to the Configure page and click the read radio button at the bottom right of the screen. A message stating "Read Successful" should appear after a successful read (Figure 17).
APPENDIX IV - SYNC TO CHANNEL Figure 17: Configure Page - Read Successful 6. To configure the hop master, change the Mode to Server and select Broadcast. Make note of the RF Channel (Figure 18). Once the appropriate changes have been made, press the Write Radio button. A Write Successful prompt will appear after a successful write. www.aerocomm.
62 APPENDIX IV - SYNC TO CHANNEL Figure 18: Hop Master Settings 7. Configure all clients that will communicate with the hop master as Clients in Auto Destination and with the same RF channel as the hop master (Figure 19) and press the Write Radio button.
APPENDIX IV - SYNC TO CHANNEL Figure 19: Client Settings 8. Set the second server as a server in broadcast mode with an RF channel at least 2-5 steps above the RF channel of the hop master. Under the radio features section, select the Sync Channel box and in the Radio RF section, set the Sync to Channel to the RF channel of the hopmaster (Figure 20). Press the Write Radio button to write the changes to the radios EEPROM. www.aerocomm.
64 APPENDIX IV - SYNC TO CHANNEL Figure 20: Server #2 Settings 9. Configure the Clients that will communicate with Server #2 as Clients in Auto Destination and with the same RF channel as Server #2 (Figure 21). Press the Write Radio to write the changes to the radios EEPROM.
APPENDIX IV - SYNC TO CHANNEL Figure 21: Client Settings I've configured my radios, what's next? Once you have configured all radios, your network should be setup similar to the one shown in Figure 22 below. The main server or hop master will need to be powered on anytime that the other servers are connected or they will never synchronize and will not be able to communicate with their clients.
66 APPENDIX IV - SYNC TO CHANNEL Figure 22: Centralized Sync-to-Channel Configuration Figure 23: Daisy Chain Sync-to-Channel Configuration
