Communication Protocol

RS485 Interface: Half-duplex communication; only one device may drive the bus at any given me, while others remain in listening mode.

TDMA Scheduling: MC-17 allocates a fixed 512 ms me slot to each RS485 device. During its slot, the assigned device has exclusive control of the bus to communicate with its slaves or transmit commands to other devices.

Early Completion: If a device completes its communication before the end of its me slot, it sends a comple on signal to MC-17, which then advances to the next scheduled device.

Message Handling 

Devices must queue their messages until their designated time slot.

Onair Medya devices support a message buffer of up to 50 messages.

If the buffer limit is exceeded, the device triggers an RS485 communication error and logs the event.

Key Features

Built-in N+1 redundancy with direct coaxial switching

Centralized bus arbitration via MC-17

Deterministic communication timing

Early slot release for opmized throughput

Error logging for buffer overflows 

No need for external changeover units