A parallel process controller capable of expandable, parallel operating multi-function control of processes. The process controller comprises programmable command memory modules, data memory modules, an input/output system, a programming panel, and a high speed data bus (N-bus).
The input/output system comprises input/output channels for intercommunication between the process controller and the external world. This intercommunication is repetitively updated for each input/output channel in an error-free manner that operates autonomously with respect to the remainder of the process controller. Each input/output channel incorporates a first dedicated area of a dedicated data memory module in which information is read and a second dedicated area of the data memory module in which information is written. The information read from the first dedicated area is transferred to external devices via a local modem-remote modem combination. Likewise, data written into the second dedicated area of the dedicated data memory module is transferred from the external device via the same remote modem-local modem combination.