6731

[chericks1]

Hi Dave,

I'm confused how to answer this, as I'm unsure how your system is set up. The DC Voltages can be measured by any board capable of analog input, but the 6731 is not. Also, the outputs from the current excited accelerometers can best be measured by a NI SCXI module. I would advise purchasing a signal conditioning module for your particular accelerometer, if you haven't done so already, and searching for this module can be done on www.ni.com/scxi.

I did a quick search and found a couple of possible modules including the SCXI-1530. If you don't already have a SCXI system, you will have to purchase an SCXI chassis (and accessories) along with the module. You would also need a DAQ board that can acquire analog inputs. I recommend using the SCXI Advisor if you're planning on making a purchase.

Does this help?

Chad AE
NI

[dmourer]

Chad,
I'm sorry. I forgot to mention that I am using a NI 4472 analog input card for my measurements. It able to read current excited accelerometers without signal conditioning. The channels that will be used to measure the accelerometers need to be AC coupled to avoid a large DC offset. My question had to do with configuring some channels for DC coupling and some for AC coupling.

Dave

[Andrew A]

Dave,

You can remove a DC offset of up to +/- 42.2V by setting a channel to AC coupled. To do so, you will need to add a DAQmx Channel Property Node. This can be found in LabVIEW All Functions >> NI Measurements >> DAQmx >> DAQmx Channel Property Node. Right-click on the default property (ActiveChans) and select Properties >> Analog Input >> General Properties >> Input Configuration >> Coupling. Then create a constant or control as an input to this property to set the AI.Coupling property to AC or DC. Each DAQmx channel can be wired (via the Task Name wire) to a different property node to set whether it is AC or DC coupled.

Cheers,

Andrew
Applications Engineer
National Instruments