TM172E28R analog outputs 4-20mA configuration

[POPE3909]

Hi Guys,

I'm trying to configure the Analog outputs (AO1,AO2) of TM172E28R expansion module to 4-20mA output (current modulation) but having problems with it.

I've configure both AO1 and AO2 as value '0' (current modulation) under Advanced Settings.

And then I do the full download. Everything complies fine with no error but when I test the outputs with a multimeter both outputs are showing around 40-50mA no matter what the programming value being 0-1000.

If I measure the AO3 and AO4 of the main controller, it correctly shows value within 4-20mA.

What am I doing wrong here?

[FedericoM · Accepted solution]

Hi,

Have you done a download all and reboot of the PLC?

Configuration is sent to expansions during the PLC boot phase.

If you have a TM171ADMI, you can disconnect the CAN bus and connect directly to the expansion using ESME HVAC Installer and TM171ADMI. Once connected you can verify the I/O settings and manually test them.