Few questions about LabView and thermocouples ( rather complicated )

[GerdW]

Hi Galjuntur,

can you convert your "TC" VI to LV2014, please?

Until then I have to look into my glass ball:

Anyone got any ideas ?

You forgot to set names for your channels?

You still use ExpressVIs?

[sprzysta]

Galjuntur
The reason why You can't success with example You show, is not compatible data type.
Right now you receiving dynamic data type from the DAQ assistant. If You want to organize signals in multiplot You just need
to use merge signals and connect it to the waveform chart.

Solutions from example You attached are proper for the scalar types.
Please analyze attached example and write a feedback.

If you want to set the names of the signals You need to use "Set Dynamic Data Attributes" VI please look into the help of that VI for more information

Regards

[Galjuntur]

Well, I tried to make virtual versions of usb 6008 ( both ) and I'm using them currently.

I tried to set names in DAQ Assistant and added these blocks - Set Dynamic Data Attributes, I set some names for first 5 channels but still, I don't have the names of the channels in my file. I don't have also names for channels on a graph, I still got plots 0-16.

I attached also my test file ( saving data to a file )

I'm trying to find a way to implement simulated inputs instead of daqs so I would work on some living signals.

//edit: I added a simulated signal instead of one daq ass, set DC with noise and I got the name of it in the chart legend ( one plot is now named DC signal with inverted noise ). I also lost 7 channels ( because of changing daq on simulated signal ) and got its name in the file.

[GerdW]

Hi Galjuntur,

your VI attachment is still in LV2015 version…

[Galjuntur]

Oh, really ? I saved it for previous versions with LV 14.0 checked. I opened that one below with LV 14.0 with LV 2012 Toolkit. So it should work now.

Maybe I should put Set Dynamic Data Att at the output of daqs and not like here, at the merge of signals.

At the moment, I am experimenting with Dyn. Data att.  I think I am supposed to change indexes of the signals in each block from 0-16 but I'm not sure.

P.S. I managed to see two names of the channels in the file and even I saw two names in the plot names of the chart. But it doesn't make sense. This is really silly to make program without having access to the sensors...

//edit: Maybe I should get attributes first and then set them just before the chart and saving to a file ? 

[GerdW]

Hi Galjuntur,

Maybe I should put Set Dynamic Data Att at the output of daqs and not like here, at the merge of signals.

This doesn't make any difference.

But you should activate the "Set Signal Name" input of SetDynamicDataAttribute and actually wire a name, if you want to change the signal names!

Your DAQAssistent already outputs signals with names, the same applies to SimulateSignal ExpressVI.

I think I am supposed to change indexes of the signals in each block from 0-16 but I'm not sure.

As said before: you need to enable the option you want to set an attribute for…

But it doesn't make sense. This is really silly to make program without having access to the sensors...

Using ExpressVIs and DDT wires extensively as you do is really silly and makes no sense! 😄

[Galjuntur]

So you want me to put strings and join them to signal index ? Or should join the Signal Index in DDTA to a wire I joined to its signal input ? [ Splitting every wire and join the ends ( two ) to signal input and signal index ] Because you said that the wires already carry the channel name so I just need to shell them out ?

BTW Does teh first output of signal splitter contain channel 0 and every output below got 1, 2,3 etc. ? Or is it mixed so it's not possible to say, which channel is where after the signal splitting ?

P.S. Sorry for being such a LV illiterate ;(

[sprzysta]

Hi again
If you merged your signals you need to specify the index before You set the name.
Im attaching the simple example how to do Your task with DAQmx.
To avoid these multiple type conversions, I'm acquiring data in double precision float type.
Then I set the names tha same way as I recommend to You. and finally I'm writing signals to the file.
Regards

[Galjuntur]

I see, so you solve this problem by naming indexes by iterations. The thing is, in this program I cannot change the names for thermometers. One change got influence on the others because of array.

I need to have named thermometers to see graphically, how corresponding to them places heat up. 

Do you suggest to leave daq assisstants and make this program on your structures I/O pchysical channels ? As I mentioned before, I will be forced to make my own scaling method for thermocouples ( external amplifiers ) so I will read voltages but this doesn't change at all in the main idea of the program.

I'm sorry for being so clunky. 

[Galjuntur]

Sorry for double posting, I made a small change and I think, it will be working as I want. 

Channels are named, everything is saved to the file and chart shows proper legend.