1769-IF4XOF2 - Setting up analog in

[mylespetro]

Yes, it is absolutely Slot 2. I have a meter that can source voltage and it is reading exactly what it should be. Not mAs on the mA input....

Have you tried the other current/mA inputs? Is input 0 still reading full scale even when you source from your meter?

 

[desertsurf520]

It reads full scale with any mA signal until I lift the wires.

I have tried other inputs. Nothing works for mA

 

[desertsurf520]

I tried channel 1 and I don't get anything on mA or Vs.

 

[joseph_e2]

The user manual says that the mA input has an input impedance of 150Ω.
What voltage do you measure between "V/I in 0-" and "I in 0+" when the sensor is connected? Do you have a way to measure mA?

 

[johnd_125]

Have you verified your V/I in0- AND your ANLG Com on your module are connected to your 24VDC-?

Have you jumpered your V In 0+ and I In 0+ together? The manual for the low res. model does not show them jumpered together. However, the manual for the fast module does.

I am feeling a sense of Deja Vu here and remember having an issue similar to yours. I believe the manual for the low res. module may be incorrect.

 

[joseph_e2]

I found a tech note (access level: Everyone):
https://rockwellautomation.custhelp.com/app/answers/answer_view/a_id/561206/loc/en_US
It says to "jumper ANLG Com to V/I in e-" where "e" is the channel number when using single-ended inputs. Not sure if that applies to you or not. That's also shown in the manual.

Another one talks about the value freezing due to noise on the line:
https://rockwellautomation.custhelp.com/app/answers/answer_view/a_id/974722/loc/en_US

I also found a note on page 87 of the manual:

The four input channels for this module are not configurable. Each
input channel supports either 4 to 20mA current or 0 to 10V dc
voltage. This choice is determined by the module terminal to which
you are wired. There is a current and a voltage terminal for each
analog channel.

So that supports the fact that there is no configuration tab in the module properties.

 

[desertsurf520]

Yes, the wiring diagram shows that the v/i neg needs to be paralled with the analog com and then to power supply negative. Thats all done correctly. Ive done that before.

I think its defective. The Voltage signal works fine. the mA does not.

 

[johnd_125]

Have you tried jumping the I in0+ and V in0+ together? If you think the module is bad anyway, what have you got to lose?

If you do replace it, I'd suggest replacing it with the 1769-IF4FXOF2F module since it has more capability and fewer issues. According to its wiring diagram the I in0+ and V in0+ will need to be jumpered together, anyway.

Let us know what you figure out.