Register Programming Example - Keithley 2601 Reference Manual

Series 2600 System SourceMeter® Instruments Reference Manual
Table D-9 (continued)
Operation event commands
1
Command
print(status.measurement buffer_available.event)
To set register bits:
status.measurement.reading_overflow.* = status.measurement.reading_overflow.SMUA B1
status.measurement.reading_overflow.* = status.measurement.reading_overflow.SMUB B2
To read registers:
print(status.measurement.reading_overflow.*)
print(status.measurement.reading_overflow.condition)
print(status.measurement.reading_overflow.event)
1. * = '.ntr', '.ptr' and '.enable'; smuX = smua or smub.

Register programming example

The command sequence below programs the instrument to generate an SRQ and set the system
summary bit in all TSP-Link nodes when the current limit on Channel A is exceeded.
status.reset()
status.measurement.current_limit.enable =
status.measurement.current_limit.SMUA
status.measurement.enable =
status.measurement.ILMT
status.system_enable = status.MSB
status.request_enable = status.MSB
Queues
The SourceMeter uses two queues, which are first-in, first-out (FIFO) queues:
• Output Queue — Used to hold response messages.
• Error Queue — Used to hold error and status messages (see
The SourceMeter status model
other registers.
Output queue
The output queue holds data that pertains to the normal operation of the instrument. For example,
when a print command is sent, the response message is placed in the Output Queue.
When data is placed in the Output Queue, the Message Available (MAV) bit in the Status Byte
Register sets. A response message is cleared from the Output Queue when it is read. The Output
Queue is considered cleared when it is empty. An empty Output Queue clears the MAV bit in the
Status Byte Register.
A message is read from the Output Queue by addressing the SourceMeter to talk.
2600S-901-01 Rev. C / January 2008
(Figure D-1) shows how the two queues are structured with the
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Bit
- Clear all registers.
- Enable current limit bit in
current limit register.
- Enable status measure
current limit bit.
- Set system summary;
enable MSB.
- Enable status SRQ MSB.
Table B-2
Appendix D: Status Model
in Appendix B).
D-27