Problem getting Keithley 6485 picoammeter to communicate with PC. Receive timeout error code 1073807339 or BFFF0015 at initialisation.

[JKLH]

More info:

•  It is connected to the PC via one RS232 - RS232 cable
• I have downloaded the IVI compliance package, the IVI drivers and the Keithly I/O layer
• Measurement and Automation Explorer:
  • Parameters used: Baud 9600, data bits 8, parity none, flow none. The baud and flow are definitely correct for the instrument but I'm not sure what the other parameters are.
  • VISA test panel: Write *IDN?\n returns 6 characters with no error. When I try to read, even only 1 byte, I get a timeout error.
  • The port never gets past the Query and Parse stage when checking it. I've tried termination characters \n, \t, \r and none (all that were offered) and there still returns a timeout error
• LabVIEW (v 8.2): I use the ke6485 drivers that were installated to open up the ke6485 initialisation vi and then subsequent others to read my measurement. It never gets past the initialisation stage and returns the error: 1073807339 "timeout expired before operation complete".
• Increasing thetimeout period doesn't rectify the issue.

Any help would be very appreciated!

[Dennis_Knutson · Accepted solution]

Check to see what type of cable you are using. It probably requires a null-modem cable but if you are using that, try a straight through cable. The manual should specify the type of cable.

[smercurio_fc]

Also try communicating with it outside of LabVIEW. On Windows HyperTerminal is a great tool to help isolate whether the issue is hardware (like a wrong cable type, as Dennis mentioned) or software (like a configuration of the serial port).

[cymrieg]

All Keithley Instruments that use serial (RS232) require a straight-thru cable.

Secondly because this is an IVI driver it is using VISA and VISA (by default) requires that the instrument send a linefeed at the end of any data it sends back so you need to select on the instrument line feed (LF) and NOT CR or CR + LF. This setting is after the baud rate and flow control and call "Tx Term".

[JKLH]

Thanks for your suggestions everyone, they are very much appreciated!

• I thought I was using a straight-through cable but it turns out it was a crossover one. I now have the correct cable.  
• I haven't tried the hyperterminal yet. I've never used it, but I'll look into it.
• I can't find where to select LF. Is this in LabVIEW, MAX or elsewhere?

Developments since I got the correct cable:

MAX: I can write *IDN?\n and then it reads and outputs "KEITHLEY INSTRUMENTS (etc.)" so there is some communication there. However I still also receive the BFFF0015 timeout error. The communication is also showed by the fact that when I execute the 'write' command the front display of the picoammeter goes into remote operation mode.

LabVIEW Instrument I/O assistant: When I 'Query and Parse' I still get the timeout error and error 113 (undefined header) is displayed on the front of the picoammeter

[cymrieg]

You are getting the whole response back from the instrument (Keithley......) but VISA is waiting for a LF character and so times out. You need to select the TX Term on the front panel of the instrument and set this to LF. It is probably set to CR.

[JKLH]

Ah thank you, I found the TX command and changed it to LF. I actually discovered that my vi works with CR as well as LF now, surprisingly. The change to LF did remove the timeout error from the MAX - vi read function. However, I still get a timeout error with the Query and Parse function of the Instrument I/O assistant in labVIEW. Saying that the actual vi I use works more or less, although I'm only getting out one reading when I'm aiming for a graph of values. Still, I think that's a different issue 🙂

Thank you for all your help!

[taylchas]

Did you ever get this issue completely resolved?  I'm having the same problems with timing out.  In MAX, I can get the Keithley serial number,etc., but not much more than that.  

[Fede_P]

Did you ever get this issue completely resolved? I'm having the same problems with timing out.