The Comnet FDC8 Series provides transmission of up to eight independent contact closures over one RS232 link or optical fiber. Microprocessor-based logic encodes the closures into ordered data packets, ensuring highly robust transmission. Garbled or out-of-sequence packets will not cause false relay changes. Mechanical latching relays maintain their state even during power loss. Each unit includes power and per-channel status LEDs to confirm contact closure activity. These modules support both stand-alone and card-mount configurations.