Why can't I get a 4-20mA signal out of a Momentum 170AAO92100 analog output module when using an ohm meter as the load?

FA198185

9/07/2020

Issue:
Why can't I get a 4-20mA signal out of a Momentum 170AAO92100 analog output module when measuring across the output channels with a meter?

Product line:
Momentum

Cause:
Hot getting any reading out of the analog card.

Resolution:
The module has a load impedance specification of 600 ohms maximum for 4-20mA, usually a meter cannot be used to verify current output due to its high impedance. Therefore, it is recommended to wire a 250 ohm load resistor across the channel and measure voltage across it. The voltage should vary 1-5vdc corresponding to 4-20mA. Alternatively, if there is an existing analog input card with a spare 4-20mA channel, then the analog output can be wired to the analog input to verify the correct current output of the 170AAO92100.