DAQ - Multi slot calibration

[jnew8916]

I am using a piece of DAQ hardware to acquire voltage outputs from 16 transducers measuring pressure in a wind tunnel. Each slot in the hardware can accommodate 2 transducers. I am able to calibrate one slot at a time using DAQ assistant, but I would like to be able to calibrate all 8 of the required slots simultaneously. Could someone please advise me on the easiest way to attempt this? Many thanks for any help.

[aNIta B]

Hi jnew,

      Can you let us know what hardware you have?  What do you mean by 'each slot' are you refering to slots in a PXI or SCXI chassis?  You may be able to accomplish your calibration using some of the lower level DAQmx VIs, but it would be good to know what kind of calibration you're currently doing and how you're doing it.  Thanks!

[jnew8916]

Hi,

I am using a PXI-1044 chassis.  At the moment I have 8 PXI-6224 DAQ boards inserted into the chassis.  Each of these DAQ boards can accommodate 2 of my transducers.  The transducers convert a pressure reading into a voltage reading, and I am aiming to produce a program which calibrate all of the transducers simultaneously.

Thanks for your assistance, if you need any more info please let me know.

[aNIta B]

Hi jnew,

      Thanks for that additional information,  it's definitely more clear what your objective is now. I think there are a few different things you could do.  The first would be to set up a custom scale for each of the channels in your task, like this example does: http://zone.ni.com/devzone/cda/epd/p/id/896 .  Otherwise, you could also 'tare' your values, like what was done in this community example. Unfortunately, there's not an easy equivalent to what you're currently doing through your DAQ Assistant.  There is the DAQmx Calibration palette by going to Measurement I/O»DAQmx»DAQmx Advanced»DAQmx Calibration, however, you'll notice that's not quite as nice as the calibration tool in the DAQ Assistant.  

Your other option would be to create a program that behaves similarly to the calibration tool, where you take a reading and calculate the offset from what it should be, then take another reading to do the same thing.  Then, based on those offsets apply a scale/offset to your entire signal.   Hope that gets you started in the right direction, let me know if that's unclear.  Have a good one!