Tektronix Keithley 2651A Reference Manual page 890

In this section:
Overview ................................................................................ 15-1
Clearing registers ................................................................. 15-13
Programming and reading registers ..................................... 15-13
Status byte and service request (SRQ) ................................ 15-15
Status register sets .............................................................. 15-20
TSP-Link system status ....................................................... 15-26
Overview
Each Keithley Instruments Model 2651A provides status registers and queues that are collectively
referred to as the status model. Through manipulation and monitoring of these registers and queues,
you can view and control various instrument events. You can include commands in your test program
that can determine if a service request (SRQ) event has occurred and the cause of the event.
The heart of the status model is the Status Byte Register. All status model registers and queues flow
into the Status Byte Register.
The entire status model is illustrated in the
Status register set contents
Typically, a status register set contains the following registers:
•
Condition (.condition): A read-only register that is constantly updated to reflect the present
operating conditions of the instrument.
•
Enable Register (.enable): A read-write register that allows a summary bit to be set when an
enabled event occurs.
•
Event Register (.event): A read-only register that sets a bit to 1 when the applicable event
occurs. If the enable register bit for that event is also set, the summary bit of the register is set
to 1.
•
Negative Transition Register (NTR) (.ntr): When a bit is set in this read-write register, it
enables a 1 to 0 change in the corresponding bit of the condition register to cause the
corresponding bit in the event register to be set.
Status model diagrams
Section 15
Status model
(on page 15-5).