DAQ - A Test to Scale

Finding the right DAQ

Our team has been investigating Data Acquisition (DAQ) devices to support our 20+ sensors and thermocouples that we want to collect data with. Our idea is to use an external analog input device instead of a PLC card. With an external device we can get a better resolution for our data collection. 

Right now our top contender is the LabJack T7 DAQ, its a Modbus TCP/IP compatible unit that can run on the same local network as the PLC. It only has 14 analog inputs, however it does have the ability to expand to 80 with a MUX board. The other attractive attribute of this device is that it has a well vetted LabVIEW driver and library. This will make the integration of the datalogging program fairly seamless with the fire control system state machine. 

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The ​LabJack U3-HV

I was lucky that one of the guys on the team had a LabJack U3-HV that I could test out with LabVIEW. The following describes the install of the software and a simple compatibility test. The goal is to determine if this DAQ works with LabVIEW therefore when we scale for the larger device we should have confidence in the purchase. 

In order to use LabVIEW both the LabJack Driver and the Library needs to be downloaded. Follow these instruction here to get setup, its pretty straight forward. After install I opened the example program "U3 Multiple IO Example.vi." I then simply plugged in the U3-HV into my PC and ran the program. The DAQ connected with program and displayed open input floating data on the front panel. To validate it was actually working I stopped the program, unplugged the USB and ran the program again. The "Error Out" displayed a connection error, this gave me the confidence that LabVIEW is actually communicating with the Device.