Data Acquisition Idea Exchange

Hello

I don't know if there is already an "idea exchange" about this, it could be usefull that USB devices or adapter support USB 3.0.

A device isn't recognized through an USB 3.0 port.

Thanks !

Vincent O.

It seems the only indication in MAX that a device is simulated is that under the Devices and Interfaces section, the tiny glyph to the left of the device name is colored yellow instead of being white/transparent.  I end up not remembering what color means what.  It would be useful to add text "Simulated" next to the device name.  It would also help to distinguish simulated devices by having the color of that glyph be green (instead of its current transparent/white) when the device is installed and detected.  Have the color change to red (and keep the existing red X) if had been detected and a device number assigned but is currently not installed/detected.  Then simulated devices being yellow may imply "warning/caution" or "not real".  Perhaps also have a help-hint popup ("Detected" or "Not Detected" or "Simulated") when the mouse hovers over device names.

Some users have expressed that they would be interested in getting a 4 port version of the USB-8502/2 CAN interface device with a metal housing, instead of plastic. 

This is pretty trivial to achieve through LabVIEW itself, but...

Signal Express is a simple, stand alone data acquisition system that allows those with limited exposure to LabVIEW set up simple test and measurement routines. One area where this is ideal - at least, for me - is in environmental or long life testing. Instead of crafting a beautiful piece of custom software for my colleagues, I can hand them a DAQ, point them in the direction of the SignalExpress and DAQmx installers, and off they go. With a little fiddling, they can create a logger that suits their needs.

One thing I've noticed, however, is that when sampling with non-simultaneous cards such as the USB 6225, users will select 1-pt-on-demand, set to some big interval, and then come back screaming at the top of their lungs - "OHMYGOD THERE'S CROSSTALK BETWEEN CHANNELS!". With a little bit of fault-finding, it's easy to point out that it's not crosstalk, but ghosting between channels, because I would guess that 1-pt-on-demand uses interval sampling and rattles through the multiplexing as quickly as it can.

My idea: give users the option to either select round-robin mode with a sensible delay, or complete control over the interchannel delay.

I realise that the standard line is usually "use LabVIEW" - I do - but I'd rather spend my time working on the important stuff and empowering those with less experience and/or exposure to make accurate measurements.

I use a PXIe-6363 which a wonderful device.   But it lacks level shifting at the digital I/O.

I would recommend that most DAQ multi-io devices support programmable and externally driven level-shifting for digital IOs.   Range for DAC driven level-shift (0.8 - 3.6, 5V),  and support for external input.   It would also be nice if multiple ports are present that some of them allow independent logic levels.  Default level should be 3.3V.    Port configurable pull-up, pull-down and latch-hold.

I rarely have to set up hardware for a new analog measurement and always have to puzzle over the difference between RSE and NRSE modes. I think of the inverting input as the reference, so "Non-Referenced Single-Ended" doesn't make sense to me. And, if I run the AISense line to my remote sensor, isn't that a Referenced Single-Ended measurement?

Yesterday, I noticed that at least some on-line documentation now refers to GRSE (Ground Referenced Single-Ended); adding that single letter helps a lot. What about adding another single letter and referring to the other mode as RRSE (Remote Referenced Single-Ended)? One letter could save a lot of people a lot of time.

When using TEDS load cells it would be useful to have a built in tare function  The null offset function only offsets the electrical value by the intialy measured amount.  This essentially shifts the calibration curve horizontally only.  The tare function could also shift the calibration curve vertically, in the load direction.  Since two point calibrations don't always create a line that goes through zero, a tare function is needed to get to zero.  Please see the attached VIs.  Also, check out my thread on this subject.

http://forums.ni.com/t5/Signal-Conditioning/9237-Null-Offset-with-TEDS/td-p/1499954

In NI MAX, mV/(m/s^2) should be added to the available choice in the dropdown menu for accelerometer sensitivity units.

(Currently avaliable choice is only mV/g and V/g)

Currently there are only two options available if you want a C-series card that has ±10V analog inputs with internal excitation voltage. Both of the available options have serious limitations which makes them impractical in dynamic testing environments. 

9218: With two input channels, it is impractical for large channel count testing. As an example at our test facility, we may run 60 analog channels which would require 30 of these cards. That would require 4 cRIO chassis' 

9219: With a max sample rate of 100 s/s, it cannot be used in a dynamic environment to accurately record data. 

There are two options that would be very beneficial to dynamic testing:

1) Add more input channels to the 9218 card so that high channel count tests don't need 3+ cRIO's. 

2) Make a new card similar to the 9218 with less capability but more input channels (No bridge, no IEPE, no ±20mA). 

For example:

± 5V, ±10V, ±60V Input Range

± 1V, ± 5V, ± 10V Internal Excitation

Minimum of 4 analog input channels.

Sample Rate 5 Ks/s

Does anyone else have a need for a card like this?

In MAX, you can open up a test panel for a DAQmx device.

I woudl like to format the numbers on the axis of the graphs. I have a calibration routine that requires that the signal get as close to 5 V as possible. When you get to less than 10mV, you the numbers on the vertical axis go from 5.01 to 5. So all you see on the graph is a bunch of 5's. It would be nice to be able to see the values in as much resolution as the channel will handle. Even at the maximum range, it can still do 2mV per bit. It would be nice to see 5.004 instead of 5.