PXI DAQ card and DMM card

[new comer]

I am new to PXI data acquisition card and its relation to the PXI DMM card.
First of all, out of curiosity could I make use of the PXI multifunction DAQ card as the DMM for the voltage and current measurement. On top of this the voltage have the range of 0 to 600VAC whereas the current ranges about 90Ampere AC. For the DC voltage and current, it have the range of 100V DC and 600Ampere DC recspectively.

On the other hand, how to multiplex the DMM for the multiple channel measurement?

[JedRetherford]

curios,

I am not sure that I fully understand everything that you are asking, so please post additional questions if my post fails to answer your inquiry.

In regards to your post, a DMM and a DAQ card have some similarities. The main similarities between these two are the ability to take both voltage and current measurements. So it may be possible to replace a DMM with a DAQ card for selected voltage and current measurements. There are however a number of things that are unique about each card. The DMM for example can measure much larger voltages and currents, the DAQ card is much more limited in the range of measurements that it can take. In addition, the DMM has the ability to take more measurents types than a DAQ card does. The DAQ card also has some unique advantages that the DMM doesn't have. The main one is multiple inputs. A DAQ board usually has 8 - 64 inputs, where as the DMM has only one. To multiplex multiple channels into a DMM, you will need to use a switch, which you can look at on the page linked below:

http://www.ni.com/switches/

I hope that information helps. If you have additional questions, please post a reply so that this forum can continue to help you.

Regards,
Jed R.
Applications Engineer
National Instruments

[new comer]

How about the resistance measurement? Could it be take care by the multifunction DAQ card?

[JedRetherford]

curios,

Please take a look at the document below:

Using a Multifunction DAQ Device to Determine the Value of an Unknown Resistor

I think that should answer your question. Please post a reply if it does not.

Regards,
Jed R.
Applications Engineer
National Instruments

[new comer]

If I choose to have a PXI multifunction DAQ, a PXI DMM which have limited channel of input,SCXI analog input and a relay matrix for the DAQ system. How to connect to the PXI DMM module from the multiple channels of multifunction DAQ? Could it be as the block diagram attached? Could you point out mistake if exit.

[JedRetherford]

curios,

I am not sure why you would want to go from the SCXI to the DAQ card to the Switches to the DMM. This is a much longer chain of devices than would normally be used. Unfortunately, from your post I am not able to understand why you might want to wire up your hardware in this way.

If you could make another post and try to post as much detail as possible about all the measurements that you are trying to make, I think that might help this forum to understand your application a little better. I would suggest a format like this:

Measurement......................Range..........Proposed Hardware
4 Voltage Measurements.......0-5 V..........AI on an M-Series DAQ Card
Strain Guage Measurement...0-.1 V.........SCXI-1520 in a SCXI-1000 chassis cabled to an M-Series DAQ Card
High Voltage Measurements..100 V.........PXI 2565 switch cabled to a PXI-4070 DMM

I think with a list like that, it might be easier to understand the exact measurements that you are trying to make and would probably make it much easier to make a hardware recommendation.

Regards,
Jed R.
Applications Engineer
National Instruments

[new comer]

The test involved measurement of voltage and current as below:
ranges
Voltage 0 - 150 Volt (AC & DC)
current 0 - 650 Ampere (AC & DC)

[JedRetherford]

curios,

In your last post, you indicated that you need to measure up to 150 V and up to 650 Amps.

With our PXI-4070 DMM you can measure up to 300 V (both DC and AC). If you need a switch to work with the 4070, so that you can multiplex a signal into the 4070, then the SCXI-1127, 1128, 1129, 1160 and 1161 would all be possibilities depending on the what other specs you are trying to meet.

However, your second spec, 650 Amps, is much too large for any of National Instruments hardware and switches to be used with. To put it in perspective, the 4070 can only measure up to 1 Amp, so the amperages that you are looking to measure are much too large for one of our DMMs or DAQ boards.

I hope that this helps to clarify what National Instruments has available for your application.


Regards,
Jed R.
Applications Engineer
National Instruments

[new comer]

I have updated the ranges of measurement of voltages, current and resistance of the planed PXI/SCXI system. I would like to look for a proposal of National Instruments hardware that need to be make available. Please advise as the suggestion will be helpfull and contribute to the development of new test station.

[new comer]

If the ranges of voltage need to be measured is between 0 to 130VAC and 0 to 50VDC,
the ranges of current need to be measured stay within 0 to 70Amp AC and 0 to 600Amp DC. Do I still need to connect voltages and current to be measured to the respective transducers (or the voltage sensor / current sensor) and the have the signal pass through the SCXI analog input (for isolation)?

There is a question if the signals stay within the maximum and minimum ranges of dmm, could I still connect it to the transducer in the first place?