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Models 2601A, 2602A, 2611A, 2612A, 2635A, 2636A
Models 2601B, 2602B, 2604B, 2611B, 2612B, 2614B, 2634B, 2635B, 2636B
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.
How do I configure the buffers to work correctly using labview?
All help appreciated
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.
- Data Collection Diagram
- (143.74 KiB) Downloaded 1430 times
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?
- Keithley Applications
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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.
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