Jump to content

Problem with Electronic Regulator Analog (4...20mA) Input to E3XB!

Recommended Posts

Hi there,

I recently started learning how to run visilogic on one of our v570 PLCs at work, but I've run into a problem when trying to input the analog signal of our SMC ITV3000 electronic regulator.

I am able to fully control the output from the PLC and control the pressure output, however I am unable to retrieve a changing analog monitor signal.

I believe I have all connections correct, and the logic in my problem should be solid. (however, even the hardware input MI doesn't read correctly)

Basically what is happening is I am getting a positive point value (around 250) however it does not change at all. So this is telling me that the signal is still being inputted, but that it is not proportional to the actual pressure, obviously.

Please let me know if you need any more information about my project and I will gladly add it to this thread. Any help would be appreciated!


Link to comment
Share on other sites

Are you using Volts or Milliamps?

Did you set the jumpers correctly on the E3xB?

Can you provide a description or sketch of how you wired them?

Did you bring power to the "0V" and "V2" terminals on the connector with the Analog outputs (this also powers the Analog input circuitry)?

Link to comment
Share on other sites

Thanks for the input Damian!

I am using 4-20ma and the jumpers are set correctly for such according to the manual.

I've attached a quick drawing on the wiring, so maybe that can help you figure out what might be wrong. Remember it is showing a value for the output, it is just not changing.


Link to comment
Share on other sites

  • MVP 2023

It looks like you've got it wired right. As a sanity check, remove the wire from the analog input terminal and put a meter set for milliamps between the black wire and the common to verify that the regulator monitor channel is working.

Joe T.

*** Edit****

Upon further review of the ITV3050 datasheet-


This regulator feedback signal is not going to work with a Unitronics analog input. The "monitor" of the regulator is a sink type and shares a common with the control input. Unitronics analog inputs are also a sink type with a common 0V connection - they are looking for a sourcing transducer.

The only way you'll be able to use the monitor signal with Unitronics is to add a loop isolator. SMC has gone the cheap route here and not included a signal generator for the monitor- they only built in a current modulator.

  • Upvote 1
Link to comment
Share on other sites

As a cheap way out.........

You can always just run the mA signal through a resistor bridge and then measure the voltage across instead. Just be careful to how you source it such that you don't overvoltate your input in the event of a wiring error. You might be able to use one of your analog outs as the source.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...