Jake Wyatt replied to syed pervez's topic in Other PLCsHi, I know that now is the year 2018, but I would like to help. I can use the Dopsoft in online simulation. First I uploaded my program to PLC. Second I started the program with the SWITCH on my PLC, then I started the online simulation in Dopsoft I used the port Com1 and it worked. It is very importatnt, that the X0 and others are only physical inputs, you can only read this variables in Dopsoft. When you want write, then you use the merkers as M0 M1 M2... I hope I could help, when you have any question write me.