DAQ

[gaks]

Hi i am working for voltage measurement using PXI 6221 M series. I have to measure voltage output of 3300XL NsV Proximity sensor and NTS 15 np hall sensor. Total number of sensor is 9. Problem is that if i disconnect few sensor then also we get same reading. I have connected negative to ground and common to other one. I have used RSE terminal configuration. Can any one help please

[Yamaeda]

Often you need a pullup resistor is my experience. How do the signals look in MAX do they work in any configuration, as Differential?

/Y

[gaks]

what is this pullup resistor? Ihave attached my block diagram.

[ABCPrograms]

A pullup resistor is not supposed to be in your block diagram, but in you electronic hardware.  Depending on how your going to messure, you will have make sure your ground are all the same or all the top levels of your voltages are the same.  Otherwise you get floating signals...

More info about it can be found here, or many other places if you just google it... 🙂

[gaks]

Even if i dont give any input then also I get some reading. Can any one tell how to remove it?..ia it possible to remove it?

[ABCPrograms]

What you are reading is noise or other signal.  That's exactly why you need to use pull-down or pullup resistors.  To clear this effect.

you can find more information here or here

[gaks]

hey i m trying to learn and using the attached block diagram but it is giving signal of one input only rest two are not showing anything. When we use DAMQmx then there we have connection diagram like where to connect what. But in this way how to give the connection?

[RavensFan]

You can't have different tasks all working on the same PXI card.  You need to combine the 3 channels into a single task.  This has the advantage that it will eliminate about 2/3 of your code.

[crossrulz]

Adding on to what Ravens said.  You need to put all of your channels into a single DAQmx task.  Then you only need one DAQmx Read to get all of the data.  I would recommend using a FOR loop to create your task.

[gaks]

Thank you,but how to know that ai0 belongs to which port like (68.67) or something else. How to choose that?