Keithley SourceMeter 2600 Series Reference Manual page 560

D-32 Status Model
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:
•
•
The SourceMeter status model
tured with the 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 mes-
sage 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.
Error queue
The Error Queue holds error and status messages. When an error or status event
occurs, a message that defines the error or status is placed in the Error Queue.
When a message is placed in the Error Queue, the Error Available (EAV) bit in the
Status Byte Register is set. An error or status message is cleared from the Error
2600S-901-01 Rev. A / May 2006
Output Queue — Used to hold response messages.
Error Queue — Used to hold error and status messages (see
Appendix B).
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Series 2600 System SourceMeters Reference Manual
--Clear all registers.
--Enable current limit bit in
--Enable status measure
--Set system summary;
--Enable status SRQ MSB.
(Figure D-1) shows how the two queues are struc-
Appendix D topics
current limit register.
current limit bit.
enable MSB.
Table B-1 in