Keithley 2220-30-1 VI help

[BDS23456]

I need to create a VI has full control over both channels, allows a user to turn knobs to adjsut voltage, run a sweep and plot the results.

All of  the NI driver components are installed. The examples can all load and run. All of the examples throw an error except for the Monitor Output VI.

The error is

Possible Reason(s):

Ke2200 Error Querry;

Instrument Reports:

170, "Invalid Command"

0,"No error"

The interface that I need to create for the 2220-30-1 must have the functionality of the image attached.

I tried to modify the Monitor Output for two channels to get familiar with creating a VI. When I chain two channels together the readings are not correct. The orginal Monitor Output works correctly.

I could use some assistance getting started with setting up the two channels and controlling the channels concurrently, setting voltages and taking voltage and current readings.

I have watched quite a few training modules.

[Dennis_Knutson]

You first need to isolate the source of the error. You can use NI-Spy/Trace to dump the commands being sent to the instrument.

Concurrent control is not possible. Instrument control is consecutive. You have not shown your modified code so it is impossible to fix what is not provided.

I would suggest you use a basic event structure and value changr events for setting the instrument parameters and use the timeout event for reading the instrument.

[BDS23456]

Thank you for the reply. Sorry for taking so long to get a reply posted.

I modified the example VI to be able to set both channels and read from both channels.This VI runs.

Errant readings are returned for this VI.

The VI must set voltages and read voltage and current.

[Edna-S]

Have you downloaded the driver from our ni.com/idnet website. http://search.ni.com/nisearch/app/main/p/bot/no/ap/tech/lang/en/pg/1/sn/ssnav:idr/q/Keithley%202000/

http://forum.keithley.com/phpBB3/viewtopic.php?f=183&t=46140

[BDS23456]

I am using the Keithely driver. Should I switch to the NI driver?

[Edna-S]

Yes please try NI driver, and see what happens

[BDS23456]

I installed the NI driver with examples. The example "Keithley 2200 Series Monitor Output" does not appear to have hooks for the multi-channel 2230-30-1. I am looking at the Block Diagram and there is no place for channel number. I also do not see any of the inputs and outputs for setting voltage and reading the results in the block diagram.  I need to set the voltage individually for the channels and take readings of voltage and current from each channel.

[PTerro]

Hi BDS23456, 

What driver in particular are you using?  I looked through and National Instruments doesn't offer a driver specifically catered to the 2230-30-1.  Our 2200 series drivers cater to the following models:

2200-20-5

2200-30-5

2200-32-3

2200-60-2

2200-72-1

I looked through the lower level subVIs of this driver in "Keithley 2200 Series Monitor Output" and nowhere is it looking to specify different voltages for multiple channels.  So these drivers are just a series of subVIs created with VISA read and write commands in LabVIEW since it is GPIB/serial communication and they are SCPI command standard compliant so if you can get the commands, that your 2230-30-1 is looking for, to set different voltages for individual channels then you could create a subVI that does this functionality. 

[Dennis_Knutson]

I don't understand the recomendations to not use the driver that is written for the particular instrument. Why use a driver that does not support the used instrument at all?

What exactly do you mean by 'errant readings'? Are you still talking about the results from the ERR? query.

[BDS23456]

Being a noob, I think I am not putting the questions well. I am slowly figuring out some of it.

The error was an incorrect voltage reading. Front panel of the power supply says X volts and VI reading is Y.

The Keithley driver is for the multi-channel newer version. The NI driver is for only the older single-channel instruments.

I removed the Keithley driver and replaced it with the NI driver. All of the icons on the VI tree are missing the input of channel number. So, if I want to use the NI driver, I have to modify all of the icons that reuqire a channel number.

Keithley is selling quite a lot of these multi-channel supplies. The NI driver should talk to these instruments.

So, I will drop back to the Keithley driver and VI tree and try to get this thing off of the ground. I have attached my from scratch VI.

What I can now use help with if choose a construct for the outer loop. The VI needs to run continuously in a laboratory setting. When a channel is enabled the voltage needs to change when a knob is adjusted.

Thanks for the help so far.