Spurious measures

Signal acquisition, processing and output
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Pablo!
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Spurious measures

Сообщение Pablo! »

I want to check all the sensors of a process, I wrote this code but there are inexistents measures.
In fact I have 5 channels that aren't physically connected but in the vi there are measures anyway.
I'm using the RSE configuration.
Suggestions?
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Andband
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Re: Spurious measures

Сообщение Andband »

Your Analog Readout VI has an Error (at least there is an Errorcode). Maybe thats the first thing you should fix.

Just make a simple test vi, that tests your AI. E. g. only one channel, displayed with a chart.
Pablo!
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Re: Spurious measures

Сообщение Pablo! »

Andband писал(а):Your Analog Readout VI has an Error (at least there is an Errorcode). Maybe thats the first thing you should fix.
It's a time-out error cause I was using the highlight execution, this isn't a problem.

For the second I don't understand you, sorry.
jg69

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Re: Spurious measures

Сообщение jg69 »

It is completely normal to measure a voltage on a channel that is floating (i.e. that is not connected to any input voltage and that is not grounded).

Jens
Andband
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Re: Spurious measures

Сообщение Andband »

ah ok.
So what you are saying is, that you are using RSE and you have nothing connected, but you are anyhow meassuring values.
That normal.
The voltage is drifting around if nothing is hooked up. Just connect something and it should be fine. If you dont have any sensor availible simply test it with a normal power supply or a battery.
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Re: Spurious measures

Сообщение Pablo! »

So I can't generate an alarm in rse mode if a sensor is disconnected?
Andband
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Re: Spurious measures

Сообщение Andband »

Additonal wires (parallel to sensor signal) between each input and the Common Ground will force the voltages to zero.
Problem: You won't meassure a sensor signal anymore (just zero).
Now try the same with 10 MOhm resistors instead of a wire and tell me if it works. It should.
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Re: Spurious measures

Сообщение Andband »

Hey Pablo. Whats up?
Have you done it? Because maybe I didn't express myself right last time:
This definitely will work.
Those inputs will be zero then - as long as nothing with a voltage output is conected.
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Re: Spurious measures

Сообщение Pablo! »

Hi andbad, excuse me but I've had a lot of problems in these weeks and I had to "forget" labview, besides I change the configuration of the input, now I'm working in differential mode but I haven't had time to test this task yet.
I hope I'll have enough time in this week.
Thank you again for your interest, I'll give you the answer as soon as I can.
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Re: Spurious measures

Сообщение Andband »

Not so important. I know that it works :D :D
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