The train of thought for designing and realizing Universal PLC configuration software (UPCS) based on programmable logic cotrooller (PLC) has been presented. On the basis of instruction code created automatically from ladder chart
the said UPCS can conveniently be used for interconnecting and communicating with different common PLCS
and monitoring online the operation of them. The said UPCS is suitable for many kinds of control network interconnected by PLCS.