Channel Wizard

[Jose Luiz Lires Domingues]

i am experiencing measurements with multiple transducers. And the hardware that i have is :
SCXI-2000 chassis
SCXI-1200 module
SCXI-1121 and a SCXI-1321 terminal block.
When i am reading from a single one strain gauge transudcer in the channel 0 that is no problem . it works on whatever vi, but the problem occurs when i put the second sensor in the channel 1. It seems the Channel Wizard (LabVIEW 5.0 / NI-DAQ 6.1) don't recognize anything, and i got lost the values that were read from channel 0. it simply does not work anymore.
I am using the multiplexed operating mode, but i am not sure.
It is possible to measure multiple sensors with the SCXI-1200 in paralel mode ?.
i will have to just acquire scans from about 4 sensors: pressure, vibr
ation, flow, temperature. But i just can do it with a single one !
Anyone help please.
Regards,
Jose Luiz.
University of Rio de Janeiro.

[Jeevan]

I am experiencing the same problem.

For my project I am attaching 4 sensors (2 LVDTS and 2 Load cells) to a analog/digital converter which in turn is connect to a NI pci-6024e daq card.

I was able to attach a signal to channel 0 of the a\d card and obtain a voltage in labview. However I have no idea how to have a second channel open at the same time to take measurements of that channel.

I have read many posts and looked at many tutorials but i am very new with labview so am having a hard time comprehending some of the material.

Also, I was wondering if anyone would know how to do the follow:

I am taking in voltages from 4 sensors. One of the sensors is a LVDT. If I calibrate the sensor and get a calibration curve, is there anyway to attach the formula for the calibration curve to a graph or waveform and if there is how do you do it?

An LVDT measures displacement so the graph would have distance on the Y axis and Time on the X-axis. Therefore when I calibrate the LVDT, I would have voltages on the y-axis and distance on the x-axis. Once I get a voltage to distance ratio\equation, how do I apply this to a graph so that I can graph continous voltages coming from a channel onto a distance vs time graph

Thanks in advance.

Jee

[chericks1]

Hi Jee,

In response to your second question, once you have the formula it is relatively easy. Bundle the distance vs time waveform with another waveform that has been through the calculations.

For example, if the relationship was voltage = distance * 2, then take the output of the acquisition VI and have the wire branch two ways. One would go into the first input of the Bundle VI, the other would be multiplied by 2, and then wired into the second input of the Bundle VI. The output of the Bundle VI would be wired into a graph.

It's very nice -- to change the Y values in a waveform graph, all you have to do is use the numeric functions on the entire waveform.

Hope this helps!

Chad AE
NI

[chericks1]

Hi Jee,

I was also checking out your first question, is there any way you can elaborate on what hardware you have?

Thanks!

Chad AE
NI

[Jeevan]

hey chad

No worries about the first part...I got some help from X from these boards. But thank you very much for the info on the formula input. I'll try it out and let you know how it goes.

Thanks man

jee