User manual

In this section:
Status register sets ......................................................... 12-1
Status byte and SRQ ...................................................... 12-2
System summary and status byte ................................... 12-3
System summary registers .............................................. 12-4
Standard event status register and enable ...................... 12-5
Operation events registers .............................................. 12-6
Questionable event register ............................................ 12-7
Measurement event register (measurement) .................. 12-8
Status function summary ................................................. 12-8
Clearing registers and queues ........................................ 12-9
Programming enable and transition registers ................ 12-10
Reading registers .......................................................... 12-11
Status byte and service request (SRQ) ......................... 12-12
Status register set specifics .......................................... 12-16
Queues ......................................................................... 12-25
The Keithley Instruments Series 3700 System Switch/Multimeter provides a
number of status registers and queues that allow the operator to monitor and
manipulate various instrument events. The heart of the status model is the
status byte register. This register can be read by the user's test program to
determine if a service request (SRQ) has occurred, and what event caused the
SRQ.
Status register sets
A typical status register set is made up of a condition register, an event register,
and an event enable register (many also have negative and positive transition
registers). A condition register is a read-only register that constantly updates to
reflect the present operating conditions of the instrument. When an event
occurs, the appropriate event register bit sets to 1. The bit remains latched to 1
until the register is reset. When an event register bit is set and its corresponding
enable bit is set (as programmed by the user), the output (summary) of the
register will set to 1, which in turn sets another bit in a lower-level register, and
ultimately sets the summary bit of the status byte register.
Section 12
Status Model