DAQmx Custom Scaling Issue

[teslaaaa]

I have created custom scaling for DAQmx. I have the following issue similar to this http://forums.ni.com/t5/Multifunction-DAQ/daqmx-custom-scaling-setup-issues/td-p/805374.

I am scaling a 0 to 5V signal to 0-100 sccm.

the slope is 20 with a Y-intercept of zero.

Everything scales fine up to 1.07V then it displays 21.56 sccm for any measurment above this voltage.

Cant figure out what i am doing wrong. I have verified the DAQ card is measuring volts correctly above 1.07 in NImax.

[teslaaaa]

IDK Whats going on i have tried to add attachments. But they arnt adding to my post.

[crossrulz]

1.07V = 21.56 (approximately)

This is sounding like a range issue on your DAQ channel.  What are you using for the maximum and minimum on your DAQ channel?  What card are you using?  Have any code you can share that shows the issue?

[Dennis_Knutson]

There are problems associated with IE and security settings. Attach as a zip.

Like the post you linked to, you have not mentioned the min and max settings.

[teslaaaa]

Added attachment. The min -10V max +10V , which is the setpints of the DAQ Card. DAQ card. NI9205

[Dennis_Knutson]

You set the min and max to the scaled values not to voltage. So you are setting the range incorrectly.

[teslaaaa]

NVMD

[Dennis_Knutson]

And your units are sccm with the custom scale. It's a trivial matter to change limits to 0-200. Did you even try this before posting your reply?

[crossrulz]

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@teslaaaa wrote:

Thats not how i read this:

	maximum value specifies in units the maximum value you expect to measure.
	minimum value specifies in units the minimum value you expect to measure.

Max values measured is -10 to +10V , If you are correct shouldnt it say "max scaled value" ?

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It is the maximum value of the number that will come out of the DAQmx driver.  Since DAQmx applies that scale for you, it is post scale value.  So you really need to put in 100 sscm for your maximum.

[teslaaaa]

Ok, so how do i programiticly change this for each channel. since each channel will have diff min/max values.