Programming instructions

Programming the Status Register System
Status Groups
Chapter 3 113
Status Groups
The Standard Operation Status Group and the Data Questionable Status Group each consist
of the following registers; the Standard Event Status Group is similar but does not have
negative or positive transition filters.
Condition
Register A condition register continuously monitors the hardware and firmware
status of the signal generator. There is no latching or buffering for a
condition register; it is updated in real time.
Negative
Transition
Filter A negative transition filter specifies the bits in the condition register that
will set corresponding bits in the event register when the condition bit
changes from 1 to 0.
Positive
Transition
Filter A positive transition filter specifies the bits in the condition register that
will set corresponding bits in the event register when the condition bit
changes from 0 to 1.
Event
Register An event register latches transition events from the condition register as
specified by the positive and negative transition filters. Bits in the event
register are latched, and once set, they remain set until cleared by either
querying the register contents or sending the *CLS command.
Event
Enable
Register An enable register specifies the bits in the event register that can generate a
summary bit. The signal generator logically ANDs corresponding bits in the
event and enable registers and ORs all the resulting bits to produce a
summary bit. Summary bits are, in turn, used by the Status Byte Register.
In general, a status group is a set of related registers whose contents are programmed to
produce status summary bits. In each status group, corresponding bits in the condition
register are filtered by the negative and positive transition filters and stored in the event
register. The contents of the event register are logically ANDed with the contents of the
enable register and the result is logically ORed to produce a status summary bit in the Status