Agilent Technologies 4294A, Programming Manual

Page: 474 / 518

474 Appendix B
Status Reporting System
General Status Register Model
General Status Register Model
The Agilent 4294A has a status reporting system to report the condition of the instrument.
Figure B-1 General Status Register Model
The status reporting system has a hierarchical structure as shown in Figure B-1. When the
instrument condition satisfies the particular condition, the corresponding bit of the event
register is set “1”. Therefore, you can check the instrument condition by reading the event
register.
When the event register bit is set to “1” and a corresponding enable register bit (a bit
marked with an arrow in Figure B-1) is also “1”, the summary bit of the status byte register
is set to “1”. You can read the status byte register by using the serial poll.
If the bit of the service request enable register is “1”, service request (SRQ) is generated
with the positive transition of the corresponding status byte register bit. By generating
SRQ, you can notify the controller that the 4294A is requesting service. This implies that
interruption by SRQ can be programmed. For more information on using SRQ, see “Using
the status register” on page 74 in Chapter 5 , “Starting a Measurement (Trigger) and
Detecting the Completion of a Measurement (End of Sweeps),” or “Using the Status
Register” on page 132 in Chapter 10 , “Handling Errors.”