The modem typically operates in a half duplex modem for vehicle telemetry between the vehicle and the control station. However, it typically operates in a simplex mode for the High Speed Telemetry Module (HSTM) in which the vehicle TX has a 50 Hz update rate between the vehicle and the receive module. The modem is designed to be a frequency hopping modem, commands to the modem are sent through either the Advanced Vehicle Processor (AVP) on the vehicle or through the Universal Target Control Station (UTSC™) in which power and frequency is set. Therefore programming is not required for use in the vehicle or at the control station. Pre-programming of the modem is necessary for the use of the HSTM since there are no commands sent to inform the modem to change frequency or power output. If powered down, the modem remembers the last programmed frequency and power output setting.
The modem comes equipped with 3 Received Signal Strength Indication (RSSI) LED for visual reference as well as an analog 0-5V RSSI output.
Signal strength is calculated based on the last four valid receive packets with the correct Cycle Redundancy Check (CRC), and represented by RSSI 1, 2, and 3. When calculating the RSSI, the master takes into account all the packets received from the slaves and repeaters. Repeaters and slaves only transmit back to the master when they have information to send. Therefore, if no data is coming back to the master then RSSI will never get updated at the master, and the LED’s will be off.
- Wide input voltage range between 8 to 34 VDC
- Adjustable transmit power (250 mW – 1 W)
- Wide temperature specifications (-40°C - +85°C)
- RSSI LED Indication – RSSI output voltage indication