I have contacted technical support in relation to this issue, but this is a more general question regarding current loops.

When you configure a channel for a current loop (as opposed to a current input), without any scaling, the logger should be 'reading' a 0-100% figure. This is related to the 4-20mA range of these current loop sensors. Is that correct?

If I have configured channels for a current loop (specifically with the internal shunt resistor, switched excitation), I should only be getting values in the 0-100 range. Anything outside that (such as 800?) makes no sense, correct? If I am getting values outside the 0-100 range, does anyone have any diagnostic advice?

I am fairly certain this is a data logger issue, as when I connect my sensors directly to the power supply, I am getting values within 4-20mA range. Is this an issue with the switched excitation?

rheem

Good morning Rheem,

Yes that is correct, think of a valve position in a processing plant 100% is fully open and 0% is fully closed.
If you see a negative reading the the loop is broken or the power isn't on.

The internal shunt resistor will depend on the wiring configuration and you need to be aware that the internal shunt is switched in and out of circuit.
This switching is so we can save power by only powering up the loop when required BUT if you have if you have other instruments reading the same loop then they will see the device as open loop.
You may also need to allow the lop device a warm up time to stabilize, this the the MD channel option. Please refer to your sensor manual for warm up times.

Cheers,
Roger