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2602A, Clearing memory which is not set up as a buffer

Models 2601, 2602, 2611, 2612, 2635, 2636
Models 2601A, 2602A, 2611A, 2612A, 2635A, 2636A
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healygeorge
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Joined: April 18th, 2013, 3:52 am
Country: Ireland

2602A, Clearing memory which is not set up as a buffer

Post by healygeorge » April 18th, 2013, 4:12 am

Hey,

I am running a test on several 2602A (firmware 2.1.6 I believe) which take over 100k current measurements. I am currently getting an error -225 "Out of memory" before the test finishes. I am using Labview 2010 on a PC over a LAN. I see on the datasheet that there is space for 100k measurements which explains why I am getting the error.

I didn't set-up or define any buffers because I don't care if I lose the vaules, I was storing them locally on the PC. In the interim I have tried setting up buffers and clearing them periodically but my measurements are not storing in the buffers I have created, instead they continue to store in the same place and I get the same -225 error.

So is there any vi in labview which will clear the non buffer memory? I can't seem to do it on the virtual front panel either.

OR

How do I configure the buffers to work correctly using labview?

All help appreciated

Jane S
Keithley Applications
Keithley Applications
Posts: 114
Joined: November 10th, 2010, 5:45 pm
Country: United States

Re: 2602A, Clearing memory which is not set up as a buffer

Post by Jane S » April 19th, 2013, 6:41 pm

Hello,
First of all, the current firmware for the 260xA SMU is in the link below.

http://www.keithley.com/support/keidoc_ ... e=Firmware

You might want to upgrade your unit.

Secondly, since you didn't mention what kind of test you are running, I am going to direct you to some sample test scripts, which you can use as a function call for LV.

http://www.keithley.com/support/keidoc_ ... t+Examples

See attached file for data collection diagram.

Jane
Attachments
DataCollection.pdf
Data Collection Diagram
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healygeorge
Posts: 2
Joined: April 18th, 2013, 3:52 am
Country: Ireland

Re: 2602A, Clearing memory which is not set up as a buffer

Post by healygeorge » April 23rd, 2013, 4:37 am

Thanks Janes S,

The data collection diagram you provided states there is a command to clear the Output Queue, the SDC command.

Is there any direct documentation on that command or how to call it?

Andrea C
Keithley Applications
Keithley Applications
Posts: 1468
Joined: October 15th, 2010, 10:35 am
Country: United States
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Re: 2602A, Clearing memory which is not set up as a buffer

Post by Andrea C » April 25th, 2013, 3:13 pm

The SDC command is the Selected Device Clear, a feature of IEEE-488 bus.

But let's revisit the buffer topic first.

Each smu channel has two dedicated buffers, smuX.nvbuffer1 and smuX.nvbufer2.
With both timestamps and sourcevalues enabled, these buffers can hold about 60K readings.
If you disable timestamps and sourcevalues, then the number of readings increases to about 140K.

In the case were these nvbuffers are not large enough, some of the 24Mb of runtime memory can be allocated to behave like a buffer by using the smuX.makebuffer(N) command where N is the number of readings you want the buffer to hold.

Both when using the nvbuffers or if using your own allocated buffers, you can clear the buffers, enable append mode, enable collecttimestamps, enable collectsourcevalues, etc.

For LabVIEW and the KE2600 Series driver, there are VIs for buffer control: make buffer, clear buffer, configure buffer, print buffer.

In order for measurements to feed into the buffer, the instrument command would be smux.measure.X(bufferName). There is a Measure VI that has a terminal for the buffer name to use. If measuring both current and voltage, then smux.measure.iv(iBufferName, vBufferName) would be the command that the VI needs to send to the instrument.

Last, in the examples group with the driver, the Advanced Sweep VI and the Factory Pulse both make use of a custom defined buffer. Perhaps these may help you.

Andrea

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