In Measurement and Automation Explorer How to get signal input range

[Karthikeyan_Mathiyalagan]

Hai ,



        In Measurement and Automation Explorer  i have configured a AI channel in that  in channel settings in Voltage input setup settings we r giving signal input range Max and Min. So how to get these values in our VI.

[Dennis_Knutson]

You can use a DAQmx Channel property node. The property node is on the DAQmx palette and there are the properties AI.Max and AI.Min. These are not the values you specified but the actual coerced min and max. In other words, if you have a DAQ device with ranges of +/- 1V and +/-5V and you specify -3 and +3, the min and max will be coerced to +/-5.

[Leorge]

Your answer is incorrect. In LabVIEW Help, Analog Input:Maximum Value Property(AI.Max) is "Specifies the maximum value you expect to measure. This value is in the units you specify with a units property. When you query this property, it returns the coerced maximum value that the device can measure with the current settings". Try my tiny program.

I think that all settings shown in task pane of NI-MAX must be readable with DAQmx channel property node.

[Leorge]

Is this a bug? An Output value of AI.Max is different to an input value of the AI.Max. Select a physical channel and run my new test program.

[Dennis_Knutson]

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@Leorge wrote:

Your answer is incorrect. In LabVIEW Help, Analog Input:Maximum Value Property(AI.Max) is "Specifies the maximum value you expect to measure. This value is in the units you specify with a units property. When you query this property, it returns the coerced maximum value that the device can measure with the current settings". Try my tiny program.

I think that all settings shown in task pane of NI-MAX must be readable with DAQmx channel property node.

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Your example seems to prove that my answer was correct. What is returned is the coerced values - just what I said would happen.

And no, this is not a bug. It is intended behavior. It is simpler to just specify an input range in terms of the expected signel instead of checking to see what are the actual ranges supported by the DAQ device. If the actual range matters in terms of learning the actual resolution for example, then you do the read.

[Leorge]

Thank you. I want to get  all values shown in NI-MAX. I guess that  more members of property is necessary such as AI.ActualMax.

Try my next program. This is the reason why I found out this page. Why error occur in a DAQmx Channel Property node?

If an indicator "AI.Max 2" is removed or a boolean "Don't use AI.Max" is  turned to true then no error occur.

Error occur with Lv2011+DAQmx9.4 or Lv8.6.1+DAQmx9.3, but no error with Lv7.1.1+DAQmx7.5.