Errors

[Jambo]

Foremost thank you for the support offered in this forum. I have two problems to which solutions or suggestions are highly appreciated. I am new into labview programming and i am currently programming the Agilent DMM device to read out voltage values from a Keithley 236 source meter using a GPIB interface. The HP 34401A subVis in available in Lab view 7.1. have be utilised for device control. After running my program, an error code BFFF0015 occurs. The actual details of this error are given as "VISA Wait on Event in Wait for RQS.VI->HP34401A Read Meas.vi->"

My second problem arises after during interfacing with Keithley 236. Upon running the program to source current values appropriate to the measurement,  for a start everything works fine, i.e. the program runs smoothly after a while and thereafter an error 0 emerges and it interupts the subsequent reading/measurement of voltage. I am using the the sub vi for Keithley 236 for lab view 7.1. The occurrence of this error seems to be random but mainly after the device is stuck in the remote and listen mode. I would appreciate your comments to help me figure a way out of this problem. Cheers

[SFK]

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@Jambo wrote:

Foremost thank you for the support offered in this forum. I have two problems to which solutions or suggestions are highly appreciated. I am new into labview programming and i am currently programming the Agilent DMM device to read out voltage values from a Keithley 236 source meter using a GPIB interface. The HP 34401A subVis in available in Lab view 7.1. have be utilised for device control. After running my program, an error code BFFF0015 occurs. The actual details of this error are given as "VISA Wait on Event in Wait for RQS.VI->HP34401A Read Meas.vi->"

My second problem arises after during interfacing with Keithley 236. Upon running the program to source current values appropriate to the measurement,  for a start everything works fine, i.e. the program runs smoothly after a while and thereafter an error 0 emerges and it interupts the subsequent reading/measurement of voltage. I am using the the sub vi for Keithley 236 for lab view 7.1. The occurrence of this error seems to be random but mainly after the device is stuck in the remote and listen mode. I would appreciate your comments to help me figure a way out of this problem. Cheers

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Hello Jambo,

I apologize for not having an instant solution to your request, and must admit that your description does leave a couple of questions open. Let me please try to straighten out your application layout:

a) You are using the HP34401A VIs to communicate with an Agilent DMM.

Q: Is the DMM you are using exactly the 34401A type, or is it any other model made by HP/Agilent?

b) You wrote that you receive the error code BFFF0015 after running your program.

Q1: Which function call causes the error?
Q2: Are you closing the GBIB session somewhere in your application and open it again, or are you using one continous session which is only closed as one of the last actions in your main VI?
Q3: Does the 'Read Block Demo' example shipped with the 34401A driver also produce this error?

c) The second problem you described is connected to the communications with a Keithley 236. If I understand you correctly, the communication does work up to a point where you receive an error code 0. This error code is thrown when the driver is called but the connection to the GPIB instrument (or GPIB card) is lost or reserved. This could be caused by a device reset or the non-closure of VISA session.

Q1: (same as Q2 above): Are you opening and closing the VISA session as they are needed, or do you keep the GPIB references open until your main application terminates?
Q2: are you using a National Instruments' GPIB card, or one from another manufacturer? In the latter case, the error code 0 could mean anything...
Q3: the Keithley 236 drivers on our website (http://sine.ni.com/apps/utf8/niid_web_display.download_page?p_id_guid=E3B19B3E9282659CE034080020E748... also feature some examples. Have you tried running them for some time? Is the same error code thrown there, too?

Best regards,
Sebastian

[A.T]

hello.

i have same problem. (second problem)

i understand that this problem is caused by a device reset or the non-closure of VISA session.

but,i don't know how do i resolve this problem.

please,give me an advice.

i want to know that how should i modify my program.

sorry,i can't make good writing due to my poor english.
 

[SFK]

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@A.T wrote:

hello.

i have same problem. (second problem)

i understand that this problem is caused by a device reset or the non-closure of VISA session.

but,i don't know how do i resolve this problem.

please,give me an advice.

i want to know that how should i modify my program.

sorry,i can't make good writing due to my poor english.
 

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Hello A.T,

to resolve this problem we will first need to find out what exactly causes the errors that you experience.

The error code 0 means that the driver could not connect to the instrument. This can happen if you are using GPIB communication in multiple, parallel loops: while one driver call initiates communication with your instrument, the specified ressource will be reserved. Any parallel calls to the same instrument will result in errors.

Parallel loops also bear the danger of closing the GPIB session too early, so that a second loop that still needs the reference will fail, as the ressource was already disposed/released.


Another possible reason for your communication failures could be that you have additional applications on your system that occupy the GPIB port, such as card diagnosis tools, GPIB instrument drivers, ...


Regards,
Sebastian

[A.T]

thank you for your advice.

i'll try to find out resource the error.

i have not enough knowledge. i have to study more.

actually,i can't understand correctly about your advice yet.

may i ask you again if i can't resolve the error after i study and try. 

[SFK]

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A.T wrote:

thank you for your advice.

i'll try to find out resource the error.

i have not enough knowledge. i have to study more.

actually,i can't understand correctly about your advice yet.

may i ask you again if i can't resolve the error after i study and try. 

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Hello A.T, of course - feel free to contact me again if you need further assistance. Best regards, Sebastian