Graph plot in labview to get time in seconds or minutes in X axis starting from 0.

[Amala]

How can we obtain time starting from 0 seconds or 0 minutes on X axis in a chart and XY graph in labview.When I plot it is showing the system time on   X axis.I would prefer the time to start from 0 ( seconds) , rather than system time.Please reply.

[margasan]

Hello Amala,

You may take a look at this example,it will show you how to start data acquisition time in zero

Start at Zero with Relative Time using Waveform Data in Charts

Warm Regards

Mart G

Applications Engineer

National Instruments Corp.

[Amala]

Can we plot diifferent types of channels (thermocouple,current,voltage) within the same NI DAQ Assisstant express vi?Also is there any disadvantage in using Express VIs compared to the legacy ones?

[shjukheter]

That depends upon your DAQ unit and number of channels. If have three channels DAQ, then you can acquire all the data and then go ahead with plotting.

DAQ assistance is also good to acquire but I recommend you to use DAQmx functions. You can also have some examples, probably, in your PC. Try search in examples as 'DAQmx'. Otherwise, you can get load of examples on this forum after a search.

[Amala]

I have NI cDAQ 9174 chasis and NI 9211 and NI 9207 for thermocouple (NI 9211) and current (NI 9207).Can I acquire all three data inputs within a single DAQ Assistant express vi.Because I tried to access all 3 in one DAQ Assisstant , but it was not accepting it.So I had to place one DAQ Assisstant for thermocouple readings and another for current.For reference I have attached my labview diagram.

[margasan]

Hello Amala,

You should be able to use just one DAQ assistant to acquire information from different modules, just add the channel and the task using the add function in the DAQ assistant see attached image

Regards,

Mart G

Applications Engineer

National Instruments