GPIB

[Eswaraiah]

Hi Friends,

I am using keithley 2400 source meter.

For my application I would like to get 100 readings per second.

Can any body help me in this regards?

Here GPIB is the control to the instrument.

[Dave01]

I am new to Labview but in the past I have used the metronome function on the timing menu.  If my math is correct, a reading every 10 ms should give you 100 readings per second.  Please see this simple example.

Dave

[JÞB]

Here

is a link to the wed site for the SMU where you can download the equipment specs.

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Eswaraiah wrote:

Hi Friends,

I am using keithley 2400 source meter.

For my application I would like to get 100 readings per second.

Can any body help me in this regards?

Here GPIB is the control to the instrument.

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100 reading per second is not ideal.  this instrument starts conversions for readings on a multiple of the line frequency so ideally you could take 60, 600 or 6000 readings per second (on US power) or  50, 500 or 5000 readings per second (on European power).  The instrument is not ideal (there is switching, set-up, and overhead that the device uses for display etc... as well as time to transfer the readings to memory or accross the GPIB bus)  achievable rates are @ 49, 167, or 256 Readings/sec in for single readings through the GPIB. 

I am curious why you need so many data points?  if you really need to take 100 samples per second you might consider a DMM or a DAQ device that is not synchronized to line frequency.

[tbob]

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Jeff Bohrer wrote:

100 reading per second is not ideal.  this instrument starts conversions for readings on a multiple of the line frequency so ideally you could take 60, 600 or 6000 readings per second (on US power) or  50, 500 or 5000 readings per second (on European power).  The instrument is not ideal (there is switching, set-up, and overhead that the device uses for display etc... as well as time to transfer the readings to memory or accross the GPIB bus)  achievable rates are @ 49, 167, or 256 Readings/sec in for single readings through the GPIB. 

I am curious why you need so many data points?  if you really need to take 100 samples per second you might consider a DMM or a DAQ device that is not synchronized to line frequency.

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Jeff is right.  I tried to take many readings per second with the 2400 once.  The throughput was much less than 100 readings per second (I forgort what it was actually, but I know it was small).  I think 60 might be the maximum.  But you will lose resolution and accuracy the higher you go in speed.

Jeff is also right about using a DAQ instead.  I don't know of any DMM's that could read at 100 readings per second.  Maybe NI's Flex DMM, PCI/PXI-4071.  To get fast readings, your best bet is a DAQ or a digitizer (scope).  You can get DAQ and Digitizer versions in USB, PCI, and PXI.