Why does my multiplexer scramble the measurements channels?

[lukd]

Good morning,

I have some problem with my data acquisition system which I have programmed with LabView2013. 

I use a multiplexer with 7 active channels which is linked with a digital multimeter. Every time I start the measurements, LabView shows me 5 measures for each channel. However, sometimes I read at the first channel the measures of another channel.. It seems that the measures shift of 1 or more channels. I have no idea about this.

Could it be a problem of my LabView routine or any hardware problems?

[GerdW]

Hi lukd,

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Could it be a problem of my LabView routine or any hardware problems?

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Yes, or yes.

😉

What kind of answer do you expect when you don't provide information?

Can you attach your VI?

Can you specify the used hardware?

[lukd]

Hi GerdW,

I use a L4411A multiplexer and a 34411A digital multimeter. Here's I attach the screenshot of the problematic part. 

[GerdW]

Hi lukd,

I'm sorry, but all I see is a small downconverted picture. Nothing to recognize…

According to Agilent the L4411A is just a multimeter, the same as the standard 34411A.

Anyway: all the information you need should be included in the manuals to your DMM/multiplexer devices!

[lukd]

I try again!

[GerdW]

Hi lukd,

you really should think about synchronizing both devices!

Right now your code to setup both devices runs in parallel with NO timing order! The DMM is started at the same time as the multiplexer is initialized…

Btw. using the AutoCleanup tool may improve your code quality a lot! 😄