The Multi-Service Data Link (MSDL) transponder is a command receiver, digital command decoder, digital telemetry encoder, telemetry transmitter, and target interface enclosed in a single lightweight package. The transponder receives commands transmitted by the ground control station and interfaces with the vehicle management computer or autopilot.
Uplink UHF command messages from the ground control station are received by the transponder in the frequency band of 359.5 MHz to 375 MHz. The RF data is converted to a serial data stream that is digitally transmitted to the vehicle autopilot for processing. The autopilot can then send a serial data stream back to the transponder where the telemetry downlink is then transmitted down to the ground control station. The MSDL has three antenna ports to support multiple antenna inputs via the vehicle RF switch. Multiple antenna inputs can be toggled through for the strongest signal.
MSDL has also been qualified per MIL-STD-461 (EMI), MIL-STD-810 (Environmental), MIL-HDBK-781 (Reliability) making it one of the most capable devices in the industry.