How to give Device-dependent command in Labview

[yash]

I am using a Keithley Programmable Current Source (Model 224). When I try to read It gives a string(containing current, V-limit, dwell time).

NDCI +n.nnnnE+n, V+n.nn00E+n, W+n.nnnnE+n

According to the manual a device-dependent command like D0X will display Source, D1X will display Voltage limit and D2X will dispaly Dwell Time. I would like know how give these device-dependent commands.

Why cann't i get the proper result using the attached vi.

[Dennis_Knutson]

Have you tested the commands in MAX? I'm not familiar with the 224 but most queries require a ? at the end in order to return results. When you send the command that gives all three results, does that work with your VI?

[yash]

Thanks Dennis

I tested the commands in MAX, But the problem still exists.

I am attaching one more file which sweeps current and reads the current and voltage (Keithley Nano voltmeter 2182). In this I am using two more device-dependent commands (F0 and F1, command X used to execute F0 and F1). F0X, F1X are working, whereas D0X, D1X, D2X are not.

[Dennis_Knutson]

You didn't include a couple subVIs so it's impossible to say what's going on but one thing I noticed with your eiarlier attachment is that you were using mode 2 for gpib read/write and in here, you're using mode 0. In the missing subVI's, do you have the address as a constant because you're not passing it in from the main VI. You should also connect up the error in/out clusters and see if you're getting any gpib errors. Lastly, Keithley has a LabVIEW driver for the 2182. Have you looked at it?

[yash]

I am including the SUB VI's here. The basic problem is to get the display of Source current reading only, with D0X command instade of all three parameters (Source current , V-limit, dwell time).

Mode 0 or Mode 2 is not giving any desired result.

Yes, in the sub Vi's GPIB address is constant. I have the driver for 2182 but it is not a problem, at least now.

[yash]

I think the D0X,D1X commands that I talked about are to display the Source , V-limit on the front panal of the instruments and not to aquire the data in source only or V-limit only form.

In order to aquire the source current reading (V-limit) alone I should formate the data string, as I did In my Sweep current VI.