PC-based programmable process rate controller

The development of an extension card for the IBM PC I/O interface card for establishing a programmable process rate controller with the PC is reported. The process rate controlling involves maintaining the process variable with reference to a variable reference input. The reference input for the process variable has a definite function of time, constituting the follow-up of several piece-wise linear regions. Each process variable has its own rate function. The extension card facilitates admitting sixteen analog inputs and one 12-bit digital input, and provides 16 analog outputs for controlling the process parameters. For meeting the requirements of modern process industries, the process rate functions of all the processes allowed in the 16 channels are made programmable