Development of Equivalent Virtual Instruments to PLC Functions and Networks

This research is a continuation to our work which was published in [1]. Eight different timing VIs are designed and tested. These include ON-Delay, OFF-Delay, Single Shot, Retriggerable Monostable, and Accumulative software-based timers. Using hardware programmable counter/timer chip (DAQ-STC-24bit) and PCI MIO-16E-1 DAQ board, another two precise timers are designed. At the end of the paper, for illustration purposes, an electro-pneumatic drive system was developed and controlled utilizing designed on-delay timers VI functions. Results of experiment show complete coincidence between the PLC-based control and Virtual PLC-based program results.