How to read Analog data ?

[whuili]

Hi,

I hope to read analog data from 2 pins on the every instrument and I have 3 instruments right now. I hope to read every data and display every data on one "DBL". Moreover, I hope to put 6 buttons on the panel and every button is corresponding to the data on every pin, when I click one button, the corresponding history 1000 stored data in the one of the six groups of data will show on a graph. How can I do that? My Labview is 6.0, and if an example can be provided, it is the best.

I have a second question: what is the difference between DAQ, VISA, GPIB and Serial functions when I hope to read Analog data from instruments? What input function should I choose?

Thanks a lot.

[Nirmal_Sharma]

Hi,

As you have not mentioned the type of instrument, i m attaching a vi where by pressing each button it generates various sine/square wave & updates to the same graph. Inside each case, put your algorithm which will read the data from the instrument & update.

For your second question, pl. read below:

DAQ functions are basically used to perform Analog inputs/output, digital & counter input/output operations from the hardware card put inside the computer system. for e.g. it might be a PXI/PCI/ISA/PCMCIA card.

VISA is common communication protocol used either for controlling & performing various operations on GPIB/Serial based instruments. Advantage here is that it uses the same functions to communicate to GPIB/serial based instruments. you nee
d to define the the resouce name (GPIB/COM port) & use the same fuctions for different type of communication. So it provides easeness to port your data either on Serial or GPIB instruments.

GPIB functinos specifically are used to perform GPIB based instrument connectivity to PC.

[whuili]

Hi, Nirmal Sharma,

Thank you for your answer and your example.

In fact, what is the more difficult for me is about the Analog input:

I have hope to readout the different pins on 3 instruments : pins 8 and 9 on AM 10 (570852.6), pins 11 and 23 on AMN PS-2A automatic matching network power supply controller (5708577-A) and pins H and J pines on RF Revision 5.00 (5708529-A). The 3 instrments are all produced by Advanced Energy Industries, INC.

When I read the values on the pins, how can I know which instrument and which pin the program is reading? I will use A/D interface card on PCI bus.

Moreover, I hope to read every value out and put them into the "DBL"s, as in my attachment file. How can I do that?

I also hope to store 1000 last da
ta for every pin, and when I click one button corresponding one pin, the graph will show its 1000 data. How can I do that?

Could you please modify the example attached by me?

Thanks a lot.

[Dennis_Knutson]

When you physically connect your A/D card to the instrument pins, you will know which instrument and pin the A/D card will be measuring. I've attached a very simple example that combines an AI Sample Channels function with what you had. The one thing I didn't do was limit the size of the data array to only the last 1000 samples.

[whuili]

Thank you very much

[whuili]

Hi, Dennis,

Thank you for your example. But, I have a question about it:

In order to display the data on 3 different devices at the same time, I think that we should use 3 "I16"s for the 3 devices' address. Why do you just use one "I16" for the 3 devices' address?

The same question is about the Channels, and we should display the data on 6 channels totally. Why do you use just one "chennel I/O " ?

Thanks a lot.

[Dennis_Knutson]

You've got, I assume, just one DAQ board to measure all of the devices. The AI Read is for the DAQ board and doesn't care whether you're measuring voltage from 1 or any number of separate devices. Hence, one device number for the single board. A single channel control will contain all of the channel names (i.e. 0-5) that you want to measure. Check out the examples that ship with LabVIEW on analog in using NI DAQ boards. If you're planning on doing something other than using the A/D board you mentioned, then please explain further.

[Nirmal_Sharma]

Dear whuili,

Can you pl. explain which DAQ card are you using & how r u selecting your instrument.

I think this can be more helpful in generating good feedbacks.

Regards,
Nirmal