Alpha RF900 Wireless Transceiver Signal Strength Software Instructions

Transcription

1 Alpha RF900 Wireless Transceiver Signal Strength Software Instructions Introduction This document explains how to use the diagnostic signal strength software to tell if there is an acceptable wireless connection between an Alpha RF900 server and one or more clients. possible sources of interference ( Appendix A Possible sources of Alpha RF900 interference on page 6) Alpha RF900 parameters ( Appendix B Alpha RF900 EEPROM parameters on page 7) Related documentation Part # Title Alpha RF900 Wireless Transceiver Instructions for Indoor Signs Alpha RF900 Wireless Transceiver Instructions for Outdoor Signs Alpha RF900 Wireless Transceiver Upgrade Instructions Aerocomm AC4490/AC4486 Users Manual (for availability, see Charge the Ni-MH battery pack The Ni-MH battery pack is used to power the RF900 client wireless transceiver. This battery pack should be charged using the supplied battery charger for approximately 8 hours before the battery pack is used. See the instructions packed with the battery charger for more information. 1. Set the battery charger switch to the Ni-MH position: Set the switch to Ni-MH. Copyright 2004 Adaptive Micro Systems LLC. All rights reserved. Adaptive Micro Systems 7840 North 86th Street Milwaukee, WI USA (fax) Trademarked names appear throughout this document. Rather than list the names and entities that own the trademarks or insert a trademark symbol with each mention of the trademarked name, the publisher states that it is using names for editorial purposes and to the benefit of the trademark owner with no intention of improperly using the trademark. The following are trademarks of Adaptive Micro Systems: Adaptive, Alpha, AlphaLert, AlphaNET, AlphaNet plus, AlphaEclipse, AlphaPremiere, AlphaTicker, AlphaVision, AlphaVision InfoTracker, Automode, BetaBrite, BetaBrite Director, BetaBrite Messaging Software, Big Dot, Director, EZ KEY II, EZ95, PagerNET, PPD, PrintPak, Serial Clock, Smart Alec, Solar, TimeNet The distinctive trade dress of this product is a trademark claimed by Adaptive Micro Systems LLC. Due to continuing product innovation, specifications in this manual are subject to change without notice. May 5, B

2 May 5, 2004 Alpha RF900 Wireless Transceiver Signal Strength Software Instructions (pn B) 2. Connect the charger to the Ni-MH battery pack as shown below, plug in the charger, and charge the battery pack for about 8 hours: Ni-MH battery pack 3. When charging is complete, connect the battery pack to the RF900 client as shown: This battery pack-to-rf900 cable is supplied with the signal strength kit. The RF900 client transceiver is identified by a CLIENT label on the bottom of the unit. 2 Charge the Ni-MH battery pack

3 Alpha RF900 Wireless Transceiver Signal Strength Software Instructions (pn B) May 5, 2004 Using the signal strength software 1. Connect an Alpha RF900 server to a computer that has AlphaNET or greater installed: Connect to a COM port Alpha RF900 server Computer cable (pn ) 2. For an accurate signal strength test, attach a properly charged Ni-MH battery pack to the Alpha RF900 client transceiver. Then place this transceiver as close as possible to the intended sign reception site. 3. Open the diagnostic signal strength application. A screen similar to the following will appear: Hop Bin Analyzer window Network Query window Signal strength in dbm (decibels per meter) Signal strength meter Using the signal strength software 3

4 May 5, Select Settings > Comm Port: Alpha RF900 Wireless Transceiver Signal Strength Software Instructions (pn B) Select the computer port that is connected to the RF900 server. Set the baud rate to Use the two sliders to set the limits for the signal strength meter. 5. Click Run Query in the Network Query window. The software will search for nearby Alpha RF900 client transceivers: After clicking Run Query, the software will search for and display nearby Alpha RF900 transceivers. NOTE: It can take up to a minute for a transceiver to respond. Also, if there are multiple transceivers, this could take several minutes. Transceiver number 4 Using the signal strength software

5 Alpha RF900 Wireless Transceiver Signal Strength Software Instructions (pn B) May 5, In the pull-down, select the transceiver number to test. Then click Run Test: Select a transceiver to test. 7. During the signal strength test a screen similar to the following will appear: Signal strength bars: Green/Yellow/Red bars = instantaneous signal strength. White bars = running average of signal strength. Signal strength meter: Green = acceptable signal strength. Yellow = marginal signal strength. Red = unacceptable signal strength. These signal strength ranges can be changed by selecting Settings > Comm Port. 26 hop bins will appear if the server and clients are using channels 0 through hop bins will appear if the server and clients are using channels 16 through For marginal or unacceptable signal strength, first try repositioning the Alpha RF900 server, then the client(s) transceivers. If neither of these produce acceptable signal strength, see Appendix A Possible sources of Alpha RF900 interference on page 6. Using the signal strength software 5

6 May 5, 2004 Alpha RF900 Wireless Transceiver Signal Strength Software Instructions (pn B) Appendix Appendix A Possible sources of Alpha RF900 interference Alpha RF900 wireless transceivers send messages using the unlicensed MHz band of the electromagnetic radio spectrum in conjunction with FHSS (Frequency Hopping Spread Spectrum) technology. Though FHSS is a very robust wireless data technology uses a technique called frequency hopping to send data. FHSS was originally developed and used by the military because FHSS transmitters are difficult to jam and have a high tolerance for radio interference. Nevertheless, any FHSS transmitter, like the Alpha RF900, is susceptible to interference from any of the following: Nearby FHSS transmitter that uses the same bandwidth as RF900 but that uses a more powerful transmitter than the Alpha RF900. (The Alpha RF900 uses a 100 milli-watt. However, a transmitter may use up to 1 watt.) Nearby DSSS transmitter can degrade RF900. DSSS (Direct Sequence Spread Spectrum) is a spread spectrum technology like FHSS, but DSSS uses a different transmission technique. Metricom Ricochet and similar wireless networks which use hundreds of 900 MHz band FHSS transmitters attached to utility poles. (Though the FCC limits the power output of unlicensed 900 MHz transmitters, the FCC does not limit how many transmitters you use or how close the transmitters are.) Nearby 900 MHz wireless phones. 1 This just means that you do not need to get a special radio license to operate an Alpha RF900 transmitter. However, the Alpha RF900 may receive interference from licensed radio spectrum users because licensed users have a higher priority than unlicensed users. Adaptive Explains What is FHSS? FHSS (Frequency Hopping Spread Spectrum) is a method of transmitting information that is virtually unjammable. Ordinary radios transmit on a narrow frequency band that can be very susceptible to interference. On the other hand, FHSS wireless transmits data on multiple frequencies, randomly hopping from one frequency to another. frequency frequency Ordinary wireless FHSS wireless FHSS origins a movie star and a piano player Today FHSS technology is used in cell phones, PDAs, wireless internet, and so on. Originally this technology was developed to guide weapons such as torpedoes. In the 1940s, German actress Hedy Lamarr and avant-garde pianist George Antheil created a Secret Communications System that could guide torpedoes to their target without being intercepted by an enemy. The system worked by sending messages between transmitter and receiver over multiple radio frequencies in a random pattern. The frequencies changed so rapidly and randomly that they were impossible to intercept or jam. Using his experience with player pianos, Antheil used paper rolls perforated with holes which formed a random frequency pattern. As long as both the transmitter and receiver used the same perforated rolls and started at the same time, they would be in sync. Lamarr and Antheil patented their system in 1942 (graphic on the left), but no one in Washington took them seriously. However, in the 1950s Sylvania scientists began experimenting with FHSS and developed military applications soon thereafter. 6 Appendix

7 Alpha RF900 Wireless Transceiver Signal Strength Software Instructions (pn B) May 5, 2004 Appendix B Alpha RF900 EEPROM parameters The following parameters are provided as a means for understanding the operation of Alpha RF900 wireless transceivers. NOTE: Alpha RF900 parameters can only be changed by sending a unit back to the factory. These parameters are changed by: opening the case of an RF900 and setting the unit to Program mode connecting the RF900 to a computer programming the unit using special diagnostic software (see sample screen below) Table 1: Alpha RF900 EEPROM parameters (b = binary number. h = hexadecimal number) # Parameter EEPROM address Length (bytes) Accepted values Value Default Server Client Description 1 Copyright 00h 29 A string similar to AEROCOMM INC. Copyright Firmware version 1Dh 8 A string similar to V Sub Hop Adjust 36h FFh 66h 66h 66h 4 Range Refresh 3Dh FFh 18h 18h 18h This value should only be changed when recommended by Aerocomm. This byte specifies the maximum amount of time a transceiver will report In Range without having heard a beacon (320 ms per increment). 0h is actually 256 x 320 ms. Appendix 7

8 May 5, 2004 Alpha RF900 Wireless Transceiver Signal Strength Software Instructions (pn B) Table 1: Alpha RF900 EEPROM parameters (b = binary number. h = hexadecimal number) # Parameter EEPROM address Length (bytes) Accepted values Value Default Server Client Description RF Channel provides a physical separation between co-located networks. The Alpha RF900 is a spread spectrum frequency hopping radio with a fixed hopping sequence. Without synchronizing the different networks to each other, different channel numbers could possibly interfere with each other and create crosstalk interference. To avoid cross-talk interference, colocated networks should use Sync-to- Channel (see Bit 5 in Control 0 on page 9). 5 RF Channel 40h h 1 00h 00h 00h A Server radio with Sync-to-Channel enabled will synchronize its frequency hop timing to a system located on the RF Channel specified by Sync Channel (see Sync Channel on page 10). The only requirement is that Sync Channel be numerically less than RF Channel. Therefore, every co-located network will be synchronizing to the network with the lowest RF Channel. Five Channel Sets are provided for the Alpha RF900, two of which are domestic: Channel Set 0 = 00-0Fh (US/Canada) Channel Set 1 = 10-2Fh (US/Canada) Co-located networks must use channels in the same Channel Set. 6 Server/Client Mode 41h 1 01 or 02h 02h 01h 02h 01h = Server. 02h = Client. 8 Appendix

9 Alpha RF900 Wireless Transceiver Signal Strength Software Instructions (pn B) May 5, 2004 Table 1: Alpha RF900 EEPROM parameters (b = binary number. h = hexadecimal number) # Parameter EEPROM address Length (bytes) Accepted values Value Default Server Client Description This two-byte value determines the baud rate used for communicating over the serial interface to a transceiver. The table below 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 below, the following equation can be used: 7 Interface Baud Rate 42h 2 42h = varies 43h = 00h 42h = E8h 43h = 00h 42h = E8h 43h = 00h 42h = E8h 43h = 00h BAUD = 100h - ( E+06 / (64 * desired baud rate)) Baud Rate BaudL (42h) BaudH (43h) Timeout 115,200 FEh 00h 2h 57,600 FCh 00h 2h 38,400 FAh 00h 2h 28,800 F8h 00h 2h 19,200 F4h 00h 2h 14,400 F0h 00h 3h 9600 E8h 00h 3h 4800 D0h 00h 5h 2400 A0h 00h 9h h 00h 11h 8 Control 0 45h b (14h) b (14h) b (14h) Settings are: Bit 7 - One Beacon: 0 = beacon every hop. 1 = beacon once per hop cycle. Bit 6 - DES (Data Encryption Standard): 0 = Send unencrypted packets. 1 = Encrypt packets. 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 = Stream Mode. 1 = Acknowledge Mode. Bit 1 - RF Delivery 2 : 0 = Addressed. 1 = Broadcast. Bit 0 - Aerocomm use only. 9 Frequency Offset 46h FFh 01h 01h 01h Protocol parameter used in conjunction with the RF Channel: 00-0Fh (US/Canada): offset = Fh (US/Canada): offset = n/a. Appendix 9

10 May 5, 2004 Alpha RF900 Wireless Transceiver Signal Strength Software Instructions (pn B) Table 1: Alpha RF900 EEPROM parameters (b = binary number. h = hexadecimal number) # Parameter 10 Transmit Retries 4Ch FFh 10h 10h 10h 11 Broadcast Attempts 12 API Control 56H 1 4Dh FFh 04h 04h 04h b (43h) b (41h) b (41h) 13 Interface Timeout 58h FFh 04h 04h 04h 14 Sync Channel 5Ah Fh 01h 01h 01h 15 RF Packet Size 5Bh FFh 46h 46h 46h 16 CTS On 5Ch FFh D2h D2h D2h 17 CTS On Hysteresis EEPROM address Length (bytes) Accepted values Value Default Server Client 5Dh FEh ACh ACh ACh Description Maximum number of times a packet is sent out in Addressed Acknowledge Mode. Number of times a packet is sent out in Broadcast Acknowledge Mode. 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 = Use Destination Server. Bit 3 - Aerocomm use only. Bit 2 - RTS Enable: 0 = RTS signal ignored. 1 = Transceiver obeys RTS signal. Bit 1 - Duplex Mode: 0 = Half duplex. 1 = Full duplex. Bit 0 - Auto Config: 0 = Use EEPROM values. 1 = Auto Configure values. Specifies a byte gap timeout, used in conjunction with RF Packet Size, to determine when a packet is complete (0.5 ms per increment). To prevent crosstalk interference between co-located networks, Sync-to-Channel can be enabled (see Bit 5 of Control 0 on page 9). Sync-to-Channel synchronizes the network timing to the co-located network using the channel specified by Sync Channel. Sync Channel must be set to any channel lower than the channel specified by RF Channel (see RF Channel on page 8). Sync Channel and Sync-to-Channel only need to be set on the server for each network. Specifies the maximum size of an RF packet. CTS will be deasserted (High) when the transmit buffer contains at least this many characters. Once CTS has been deasserted, CTS will be reasserted (Low) when the transmit buffer contains this many or less characters. 10 Appendix

11 Alpha RF900 Wireless Transceiver Signal Strength Software Instructions (pn B) May 5, 2004 Table 1: Alpha RF900 EEPROM parameters (b = binary number. h = hexadecimal number) # Parameter EEPROM address Length (bytes) Accepted values Value Default Server Client Description Provides a means for controlling the RF transmit output power of the RF900. 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. 18 Maximum Power 63h FFh 60h 60h 60h Max Power (address 63h) 100% Transmit Current (ma) Transmit Power Output (dbm) 00h h h h h h h h h h Ah Bh Ch Dh Eh Fh Eh h Modem Mode 6Eh 1 E3h, FFh FFh FFh FFh 20 Parity Mode 6Fh 1 E3h, FFh FFh FFh FFh 21 RS485 DE 7Fh 1 E3h, FFh FFh FFh FFh 22 Destination Address 70h 6 E3h = Enable Modem Mode. FFh = Disable Modem Mode. E3h = Enable Parity Mode. FFh = Disable Parity Mode. E3h = GO0 is active low DE for control of external RS485 hardware. FFh = Disable RS485 DE mode. The MAC address of the intended receiver on the network. 23 System ID 76h FFh 01h 01h 01h System ID is similar to a password character 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, regardless of channel number. 24 MAC ID 80h 6 Unique IEEE MAC address. Appendix 11

12 May 5, 2004 Alpha RF900 Wireless Transceiver Signal Strength Software Instructions (pn B) Table 1: Alpha RF900 EEPROM parameters (b = binary number. h = hexadecimal number) # Parameter EEPROM address Length (bytes) Accepted values Value Default Server Client Description 25 D.O.B. E0h 4 Date Of Birth specifies the date that the transceiver was originally tested/ calibrated. This is a value stored in packed BCD (Binary Coded Decimal), for example: 05h 07h 20h 02h = 05/07/2002. NOTES: 1 Because only channels sets 1 and 2 are available for use in the US and Canada, the actual number of channels that can be used is from 0 to 2Fh (0 to 47 decimal which amounts to 48 channels). 2 In Addressed Mode, the RF data packet is sent out to the receiver designated by the destination address (see Destination Address on page 11). In Acknowledge Mode (see Bit 2 in Control 0 on page 9), Transmit Retries (see Transmit Retries on page 10) is used to increase the odds of successful delivery. In Stream Mode (see Bit 2 in Control 0 on page 9), the RF data packet is just sent once. In Broadcast Mode, the RF data packet is sent out to all available receivers on the network. In Acknowledge Mode, Broadcast Attempts (see Broadcast Attempts on page 10) is used to increase the odds of successful delivery. 12 Appendix