NI9226 2 wire PT1000 LabVIEW 2018

[Marken]

Hi There,

I am trying to write a VI that will read 8 x 2 wire PT1000 connected to NI9226.

For start, I've only connected the first three channels.

It seems that if I configure the DAQmx create channel AI temperature RTD for two-wire configuration then the DAQmx Read (Analogue DBL 1Chan 1Samp.vi comes up with an error;

Possible reason(s):

Requested value is not a supported value for this property. The property value may be invalid because it conflicts with another property.

Property: AI.ResistanceCfg
Requested Value: 2-Wire
Possible Values: 3-Wire, 4-Wire

Channel Name: Temperatures0

How do I successfully read 8 x analogue channels connected to 8 PT1000 RTD's?

I've attached my VI, please help!!

Regards

Mark

[RavensFan]

I think what you'll have to do is  set it up for 3 wire and jumper in the 3rd terminal to one side.

Or set for 4 wire and jumper in both terminals, one to each side.

[GerdW · Accepted solution]

Hi Marken,

in case of such problems you should read the datasheet of the DAQ module! (You probably should do this even before problems arise!)

It clearly states the NI9226 supports only 3-wire and 4-wire Pt1000 sensors.

(Why don't you fake a 3-wire sensor by connecting RTD- and COM?)

[Marken]

Hi GerdW,

Thank you very much for your reply.

The suggested solution did the trick that I was looking for.

I can't help myself to mention that reassured I DO read the datasheet of the hardware before order and use. I could say gently that is a different situation that we engineers deal with. The card has been purchased for a different purpose by a different department. I was asked by my manager to see if I can connect some two-wire cheap PT1000 and read the temperature for a quick thermal test.

Again thank you for your time and have a lovely weekend.