Read method for Keithley 6485

[960310]

I wrote a kit for Keithley 6485 model picoammeter. But it doesn't work. Instrument has given an error and "TALK" indicator has activated. I attached the kit. Please could you help me. Thanks

[Dennis_Knutson]

You will need to read the manual to determine what you have to write to the instrument in order to command it to take a reading (i.e. READ?). After you add the write, then you should be able to do a read. I would recomend you debug the write and read in MAX (right click on the instrument and select 'Communicate with Instrument'). I would also recomend that you use VISA Read and VISA Write functions instead of the lower level GPIB. Keithley also has an IVI instrument driver for it so you should consider using that instead of reinventing the wheel with custom code.

p.s. You have a VI there, not a 'kit'.

[960310]

Thank you, Dennis.

I am giong to try your recommends.I will syncronize Keithley 6485 and LakeShore 331S temperature controller in a vi. I wrote a vi for 331S in GPIB. and, I don't know VISA using. I downloaded original driver from http://sine.ni.com/apps/utf8/niid_web_display.download_page?p_id_guid=7094CC81B2146DD9E04400144FB7D2... and I entered GPIB0::14::INSTR to box of VISA resource name and/or VISA resource name out. but, it wasn't work. There is a error in my every thread. There are to many vi in a package for me.so, I don't know which vi will run first. I use Labview 8.5 version.

 Thanks again.

[Dennis_Knutson]

You don't type in the VISA Resource Control. You use the little arrow on the right side to select the actual resource name. In MAX, do a scan for instruments and make sure everything is detected.

If you get an error, you really have to provide the error number for someone to help.

p.s. You've downloaded a project style driver. An example should be there. Just open the example finder and look for one (Find Examples>Hardware Input and Output>Instrument Drivers>LabVIEW Plug and Play).

Message Edited by Dennis Knutson on 05-09-2010 04:43 PM

[Snowman 6008]

What Dennis recommended is good practice. Before you try to use an instrument driver (such as the VI you have downloaded) which is different from the driver needed to communicate with the gpib card in your computer (488.2 or VISA) it is best to try writing a simple query to your device in MAX such as *IDN?\n

You can do this using viwrite, and verify that the command was successful using viread. Let us know if you can successfully query and get information from the instrument using VISA.

[micronfab]

I'm currently (excuse the pun) also using the Keithley 6485. I found the easiest way to to initialize it and read data was to use the examples available on the Keithley website. You do however also have to download their 'Keithley Input Output Layer' code to make them work. I downloaded version C02, assuming it was the latest version available.

http://www.keithley.co.uk/data?asset=52766

I tried running your VI on my computer and it didnt work also. 

Heres the stripped down VI that works for me (if it successfully attaches! My first reply on here).

It's for LV9, so hope it works on LV8.5 also.