English
Communication server PLCComS provides TCP/IP connection between client device and PLC.
Server communication with clients is solved using a simple text-oriented protocol REQUEST/ANSWER. Therefore, the client queries the server by commands for the values of variables whose names are symbolic and are described in public file. However, it is possible to use direct addressing.
Server sends to client only error messages and variables whose values have changed. That is, if the variables are allowed.
Server communicates with the PLC using the optimized protocol EPSNET. The values of allowed variables are polled by absolute addressing and periodically in time increments of 100ms.