Anritsu MT9812B, Operation Manual, Page: 110 / 144

Section 5 Remote Control
5-42
5.10 Status Commands
This paragraph explains the device status report and the data structure defined by
the IEEE488.2 standards.
Each status register has the following configuration.
(1) CONDITION REGISTER
The condition register remains unchanged even after reading from the exter-
nal device (controller). It cannot be set by any of the commands from the
external device (controller) and can be set only by the state change in the
measuring instrument.
(2) TRANSITION FILTER
The transition filter is used to determine whether to report the state change
reported to the condition register to the event status register.
The filter for change from 0 to 1 is called the P-transition filter, while the
filter for change from 1 to 0 is called the N-transition filter. These filters are
rewritten as a mask pattern in accordance with the request from the external
device (controller) (set/clear for each bit). These mask patterns remain un-
changed even after the reading from the controller.
(3) EVENT REGISTER
The event register can be set indirectly through the condition register or the
P/N-transition filter from the inside of the measuring instrument. The event
resister cannot be directly accessed from an application program.
(4) EVENT ENABLE REGISTER
An event enable register for the event register.
(5) ERROR/EVENT QUEUE
While a message is stored in this queue, the corresponding bit in the status
byte register is set. If a message goes out of the message queue, the corre-
sponding bit in the status byte register is cleared.