The FDM001 (VME) / FDM002 (ISA) SGLS Signal Demodulator is a high performance FSK/AM demodulator that receives and demodulates the standard Space Ground Link System (SGLS) FSK/AM tri-tone signal. It reproduces 1, 0, and S ternary data outputs with a coherent command clock derived from the received SGLS modulated subcarrier tri-tone signals (65 KHz, 76 KHz, 95 Khz) at command rates of 1 Kbps and 2 Kbps. The command data rate is automatically detected. The Demodulator accepts one SGLS signal input, and provides both TTL and RS422 ternary (1,0,S) data and clock outputs. A squelch capability is provided to inhibit data output when the input signal drops below a preset threshold. No user setup or control is required.
The card is a single-slot 6U x 160 mm VME module (FDM001) or ISA module (FDM002). SMA interface connectors for the Demodulator signal input (INPUT), TTL outputs (S,0,1, & CLK) and the RS422 output (RS422 DATA/ CLOCK) are accessible at the front panel. Three sync status LEDs are located on the front panel.
• Zero(0)-Hz IF SGLS Demodulator
• Performance to within 1 dB of theoretical for Eb/No of 10 dB
• Auto-rate detection between two command data rates, 1 kbps and 2 kbps; or
• Fixed single rate detection, selectable, 1 kbps or 2 kbps