S7-200 Communication Problem

Hello Guys,
I'm using S7-200 PLC to run Conveyor System.
I have a problem in communicating S7-200 PLC when the conveyor system starts to run. I can't no more read the PLC or the communication fails.
but when I use Laptop to communicate S7-200 while the conveyor system is , running the communication is good.

Is there a problem in my wiring connection? or other problem in my system?
Will you please help me with this?

Strange... Have you checked the voltage? put your meter on the power to the CPU and see if it drops when the conveyor starts, it may dropping low enough to stop your coms for just a sec then MicroWin will error out

Thank you for quick reply.
I tried checking the power of the CPU and it's okay.
There might be a problem in a ground connection of the CPU.

by the way, my computer will reboot when the conveyor starts to run.