A typical connection used to transmit/receive ARINC data might consist of a cable and a connector similar to the one shown below. Although ARINC transmit/receive channels aren't the only thing this interface can be used for. I've noticed that several different varieties of LRU also use some of the pin connections for I/O discretes.
So, are the I/O discretes considered to be part of the ARINC interface? Or do they just coincidentally share the same connector and have nothing to do with ARINC?
As one of the answers commented on... I am not talking about the discrete bits within an ARINC word but the physical discrete I/O voltage signals that you'd see on an avionics bus.