Error in the registries, 4-20mA

Question

I´m using fieldpoints (FP-2020) to register the values (4-20mA) originating of a CFI (converter frequency - current). In some occasions fieldpoints have registered erroneos values, as if the CFI was not connected.
Is it possible that fieldpoint varie the impedance that the CFI is seeing and this alters the measures?
The CFI is VM9-F460 of "Bureau Wittich & Visser"
Thanks.
In spanish:
Estoy usando un fieldpoint (FP-2020) para registrar los valores (4-20mA) provenientes de un CFI (conversor frecuencia - corriente). En algunas ocasiones el fieldpoint ha registrado valores erroneos, como si el CFI no estuviera conectado.
Es posible que el fieldpoint varie la impedancia que el CFI está viendo y esto altere las medidas.
El
CFI es VM9-F460 de "Bureau Wittich & Visser"

Answer 1

Mikel,
One issue that a lot of people have with the TB-10 and the dual channel modules is that they don't get them seated in properly. This can cause a variety of issues one of which is intermittent behavior. Check to verify the following:
1. Make sure that both the top and bottom snaps are snapped in completely.
2. You should hear the two distinct snaps when putting the dual channel module into its slot.
3. Also make sure that the pins on the bottom side are not bent as one could have inadvertently bent the pins.
4. The red sticker on the TB-10 Dual channel module should always be on the top, away from the screw terminal.
I attached a Word document that has two images of how dual channel modules should and shouldn't look w
hen seated in the TB-10.
Next time you notice this intermittent behavior inspect the TB-10 and watch the Power and Ready lights to see if they are flickering or not. If the LEDs flicker than this implies that there are probably other issues. Is your TB-10 full of dual channel modules or does it have just the FP-AI-C420? What version of LabVIEW do you have? What version of NI FieldPoint?
Ames
Attachments:
TB10.doc ‏709 KB