Read power meter in LabVIEW via RS-232/RS-485

[sunil75]

Hi Crossrulz

I have downloaded Keithley 24XX meter driver and NI VISA 14.0.1. I have installed NI VISA 14.0.1 but have no idea what to do with Keithley 24XX meter driver.

What to do next?

Thanks

Sunil 

[crossrulz]

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@sunil75 wrote:

Hi Crossrulz

I have downloaded Keithley 24XX meter driver and NI VISA 14.0.1. I have installed NI VISA 14.0.1 but have no idea what to do with Keithley 24XX meter driver.

What to do next?

Thanks

Sunil 

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Like I said, there should be an example in there.  Find it and study it.

[Dennis_Knutson]

You should know that all project style drivers include at least one example and the example will be listed with Help>Find Examples>Hardware Input and Output.

[sunil75]

I have established connection between keithley 2401 and lab view.

When I run an example VI 'Keithley 24XX'  Rea Single, I am getting an error :

'Error -1073807346 occurred at VISA Write in Keithley 24XX.lvlib:Error Query.vi->Keithley 24XX.lvlib:Configure Measurement.vi->Keithley 24XX Read Single.vi'

'Possible reason(s):

VISA:  (Hex 0xBFFF000E) The given session or object reference is invalid.'

How to fix this problem?

[Dennis_Knutson]

Use the correct VISA reference. You should be selecting the com port from the pull-down menu of the VISA Resource Name control.

[sunil75]

I am using RS-232 with plug and play drivers. I made the connection and selected COM in visa resource name

Still I am getting error.

Any suggestions

Thanks

[Dennis_Knutson]

In the MAX VISA test panels, can you select the port and get a response with the *IDN? query?

[sunil75]

Thanks guys. it is working now. There was some issue with the termination character.

[maurlind]

Hi CollindWit!

So, today I got my usb adapter RS-485. I tried som examples but I can't  get it to work. I have installed drivers for the adapter and selected the right com port in the visa resource name. The device that I want to connect with has the same baud rate as the usb-adapter. 

I have tried using the VISA  Interactive control and done some test with the write function with *IDN?\n command. When i write this I get a green  lamp blinking om my usb-adapter and a return count of 6 bytes. But when I'm testing the read function I get:  VISA:  (Hex 0xBFFF0015) Timeout expired before operation completed.

What am I missing?

My power meter has alot of different menus that you can access, but I just want  information on 2 or 3 to log the data in real time. I know that I have to write a adress to the device to access the right menu and then read the data that I'm receving.

Do I do this in the wrtite buffer in the visa write function, is there a special way that you have to write it? In the device protocol there is different adress for accessing diffrent menus. For example if I want to access sum of power the the modicom adress is 300051, the physical adress is  0032h and the word length is 2. 

Can VISA read/write function only work with inputs of ASCII or can I write the address above in the write buffer directly or is there something else you have to do first?

It seems that the adapter is working and the serial com port aswell, but I cant find a way to speak with my device, what I'm I doing wrong?

I'm attaching the program that I have tried to use. 

Best regards Maurlind!

[Dennis_Knutson]

This thread is confusing because of the different threads.

It is silly to send idn to a modus device. You can't just make up the command to send. I can't look at your VI right now but if you aren't using the modbus library, you are going to have more problems than a beginner can solve.