cskaggs2
Member
I have a machine that has two 24VDC power supplies. One power supply is for a vision system (recommended to be isolated power supply by the vision system supplier). The 2nd power supply is for the PLC and all other I/O.
As it was originally wired by the machine builder, the vision system was powered by one power supply, but the I/O on the vision system was powered by another power supply. This gave a voltage difference of 24V between the power common for the vision system and the I/O common. This is specifically cautioned against in the manual for the vision system.
When I tried to power the I/O for the vision system from the same power supply that powers the rest of the vision system, my input to the PLC from the vision system would not work. The only way I could get things working for now was to power the PLC, vision system, and other I/O's all off the same power supply.
I know it can be done with separate 24VDC power supplies. I think it has to do something with the grounds. Can someone help explain this for me?
Thanks,
Chris
As it was originally wired by the machine builder, the vision system was powered by one power supply, but the I/O on the vision system was powered by another power supply. This gave a voltage difference of 24V between the power common for the vision system and the I/O common. This is specifically cautioned against in the manual for the vision system.
When I tried to power the I/O for the vision system from the same power supply that powers the rest of the vision system, my input to the PLC from the vision system would not work. The only way I could get things working for now was to power the PLC, vision system, and other I/O's all off the same power supply.
I know it can be done with separate 24VDC power supplies. I think it has to do something with the grounds. Can someone help explain this for me?
Thanks,
Chris