Specifications

318 Appendix B

Status Reporting System

General Status Register Model

The Agilent 4287A 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 satisfies a particular condition, the corresponding bit of the event register is set

to 1.Therefore, you can check the instrument status 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,” a service request (SRQ) is generated

by the positive transition of the corresponding status byte register bit. By generating SRQ,

you can notify the controller that the 4287A is requesting service. In other words,

interruption by SRQ can be programmed. For more information on using SRQ, see

“Waiting for (Detecting) End of Measurement” on page 70 in Chapter 5, “Starting

Measurement Cycle (Triggering) and Detecting End of Measurement,” or “Using the

Status Reporting System” on page 135 in Chapter 10, “Error Handling,”.