The 45C29 is a Process Control Gateway created by Reliance Electric. depending on what year it was actually produced, this card may have been also sold by Baldor Reliance or Asea Brown Boveri.
The 45C29 is an R-NET Process Control Gateway (or PC Gateways) that can function as a MODBUS slave and can use a standard RS-232 interface. This interface will take commands from the system and then send them to other Reliance devices on the R-NET. The host has to always initiate all commands on this network. When the 45C29 receives commands through the network from the host it will then translate them AutoMate communications protocols. The only command that will not function through the R-NET is the Loopback Test and that is because this test is performed directly through the PC Gateway.
When a message is received by a 45C29, it will do these three things. It will check the message format and either pass along the message or ignore it depending on the formatting. The 45C29 will then check the address of the message it has received and then either not send it or delete it from the system. The last thing the 45C29 will do is check to see that the All Pass option is available and then it will be sent through.
The 45C29 is enclosed in a black rectangular enclosure. It has four LED lights on it that are labeled POWER, READY, XMIT, and RECV. This device uses a 250V AC 3AG 1amp Fuse that can be replaced. There are 6 screw-type connections on a terminal strip labeled L1, L2, 115, 230, and 2 labeled READY. On the front faceplate, there is also a place for a coaxial cable and a female ETA communication connector.