Service Request Programming Example; Polling For Srqs; How Do I Store Measurements In Nonvolatile Memory - Keithley 2651A Reference Manual

Section 9: Frequently asked questions (FAQs) Model 2651A High Power System SourceMeter® Instrument Reference Manual

Service request programming example

The example below shows how to program the Model 2651A to generate an SRQ when the current
limit on channel A is exceeded.
-- Clear all registers.
status.reset()
-- Enable current limit bit in current limit register.
status.measurement.current_limit.enable = status.measurement.current_limit.SMUA
-- Enable status measure current limit bit.
status.measurement.enable = status.measurement.ILMT
-- Enable status SRQ MSB.
status.request_enable = status.MSB

Polling for SRQs

To determine if the Model 2651A is the GPIB device that generated the SRQ, serial poll the unit for
the status byte, and test to see if the corresponding summary bits are set.

How do I store measurements in nonvolatile memory?

After the measurements are complete, you can save the reading buffer data to the nonvolatile
memory in the instrument. An SMU has two dedicated reading buffers for measured readings, source
values, and timestamps: Buffer 1 (nvbuffer1) and Buffer 2 (nvbuffer2). Reading buffers can be
saved to nonvolatile memory so that saved data will load automatically when power is cycled. For
additional information, see
9-4
Saving reading buffers (on page 3-8).
2651A-901-01 Rev. A / March 2011