R A Peterson
By accident I have discovered a nifty feature of the AB SLC5/05. I am not sure how many of the SLC5s do this but its a great help in creating simulation routines as part of checkout. It is possible to write to input addresses in the PLC program! By disabling the slot the input is in, the PLc will not update the inputs, and you can write a simulation routine that actually writes to the input bit. usually I have written simulation routines using intermediate buffers for the inputs, but this adds a layer of complexity that is not now necessary, at least in a 5/05. typical simulation routines: turn on motor feedback bits when the program turns on the control output ramp up PVs for loops when loop is put into auto ramp up flow meters when valve opens to test integration routines this allows you to do extensive testing without having any actual inputs.