Wiring question for Unitronics PLC

Hello ,

I am new to the PLC world, so apologies if the question is stupid.

I have a Unitronics PLC UIS-070-B10 with a digital i/o module UID-W1616R.
My inputs are wired in this configuration as per the installation guide:
And the outputs are wired like this, also from the installation guide:
I`ve written a simple test program, to test if all the inputs/outputs are working properly.

On the back of the UID-W1616R module, I can see the inputs and outputs coming on and off as per the created program and I can hear the relays inside in the PLC switching on and off, but I am not getting the 24 volts out of the outputs. How do I fix the problem?

Could the problem be the wiring configuration of the inputs? And if so, would wiring them like this fix it?

Thanks in advance!

No.

The wiring for the outputs looks suspect, I would have expected the common side of the devices to be connected to 0v.

(you may want to review the documentation, I found more of what I expected at their website for wiring outputs)

jstolaruk said:

No.

The wiring for the outputs looks suspect, I would have expected the common side of the devices to be connected to 0v.

(you may want to review the documentation, I found more of what I expected at their website for wiring outputs)

Click to expand...

Thats what I thought too, so I had the common connected to the CM terminal and 0V, but I had the same problem then as I have now.

Could you please link what you found on their website, because I cannot find anything regarding wiring.

Thank you very much for your reply

The UID-W1616R has relay outputs.

What do you have wired into the CM terminal? Do you have 24volt present on the CM terminal?

mitachky said:

Thats what I thought too, so I had the common connected to the CM terminal and 0V, but I had the same problem then as I have now.

Could you please link what you found on their website, because I cannot find anything regarding wiring.

Thank you very much for your reply

Click to expand...

Looking specifically at that module, I found this document. The 24V connection is not for the devices, but for the PLC. The power source for the devices connected to the outputs is wired between the device commons and the respective CMx connection. see page 7.

Yup, as blperkins said, if you want 24V to be present at the output terminals when an input turns on, you must have the CM terminal wired to +24V. You can also wire the CM terminal to 0V, but you would only do this if you want a current sinking output which is nowhere near as common as a sourcing output.

Thank you so much guys I will try it as soon as possible and I hope it works that way. Much appreciated!

@jstolaruk
Thank you very much sir! That makes a lot of sense now. I guess I just couldnt read the diagram in the installation guide!