Keysight E4981A - Event Register; Enable Register; Status Byte Register; Condition Register and Transition Filter

364 Keysight E4981A 120 Hz/1 kHz/1 MHz Capacitance Meter
Status Reporting System
General Status Register Model
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Event register
The event register reflects the corresponding condition of the E4981A (e.g.,
occurrence of an event) as a bit status. These bits continuously monitor
changes in the E4981A’s state and change the bit status when the condition
(e.g., change bit status to “1” if a specific event occurs) for each bit is met. You
cannot change the bit status by issuing a SCPI command.
The Keysight E4981A has the following event registers:
• Standard Event Status Register (see Table C-2 for details.)
• Operation Status Event Register (see Table C-3 for details.)
Enable register
Setting the enable register allows you to specify event register bits that can set
“1” to the summary bit of the status byte register when an event occurs. The
register bits work as mask bits; setting “1” to an enable register will enable a
corresponding bit in the event register.
For example, when you want to set “1” as the summary bit in the status byte
register by a specific register condition, set the corresponding enable register
to “1.”
Status byte register
If the enabled event register is set to “1,” a corresponding bit of the status byte
register is also set to “1.” This register also indicates the output queue and SRQ
status.
The value of the status byte register can be read by using the *STB? command
on page 162 or the serial poll (SPOLL statement in HTBasic) from the
controller. The *STB? command sets the analyzer to remote mode. On the
other hand, the SPOLL statement in HTBasic reads the status byte register
value directly without the instrument being set to remote. Therefore, you can
continue to operate the front panel keys while a controller is reading the status
byte register.
Reading the status byte register by using the *STB? command does not affect
the contents of the status byte register. However, reading it with the SPOLL
statement of HTBasic will clear the RQS bit in the status byte register.
Setting the service request enable register using the *SRE on page 162 can
generate a service request synchronously with the status byte register.
Condition register and transition filter
When the status register has a transition filter, there is a lower register called a
condition register under the event register. The transition filter is between the
event register and the condition register.