SSR connection with a Digital Output I/O module

Hello all,

I am a student in a laboratory, new to the system. We have a machine I want to implement a PID heating system. I have understood the software side but hardware.

I use SNAP-ODC5A-I module and connect to SSR unit. I have realized I cannot get 5V DC from I/O module to activate the SSR unit. Instead I measure ~5 mV with multimeter. How can I do a proper connection, do I miss a point?

Thank you very much!

You will need a 5V DC power supply in your “loop”. The module acts as a switch, it does not provide voltage.

Thanks Philip,

So do you suggest a diagram like that?

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Yes, that diagram looks good.

EDIT: Same will be required for the SSR, its just a switch, so you will need a power supply of the correct voltage and current for the load that the SSR will be switching.

Thanks Beno, yes that’s the idea the SSR switch is getting activated >3 V DC.
So I suppose in that diagram I can use the Snap module to control the SSR with a PID loop.

Yes. The PID will be setup for TPO. Time Proportional Output.
There are lots of posts here in the forums on TPO and there are mentions of it in the PID guide and the PAC Control command reference as well.

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