Specifications

11 2 Chapter 5

Measurement Start and Detection of Measurement End

Waiting for Measurement End (Detection of Sweep End)

Using the Status Register

The state of the E4991A can be monitored through status registers. This section explains

how to detect measurement end by using status registers. For details on the status report

system, including bit configuration of status registers, see

B, “GPIB Status Report

System,” on page 555.

The Operation Status Event Register (see Table B-3 on page 565) indicates a measurement

state. A Service Request (SRQ) is useful for detecting a measurement termination based on

this information.

Use one of the following commands to detect a measurement end by using SRQ.

• *SRE on page 283

• STAT:OPER:ENAB on page 490

• STAT:OPER:PTR on page 492

• STAT:OPER:NTR on page 491

Perform the following procedure to detect a measurement end.

Step 1. Configure the E4991A to generate an SRQ when the Measuring bit (set to 1 during

measurement) in the Operation Status Event Register changes from 1 to 0.

Step 2. Make a trigger to start measurement.

Step 3. When the SRQ is generated, an interrupt is executed in the program.

NOTE If sweep averaging is enabled, the E4991A generates an SRQ after measurement is made

the same number of times as that of the sweep averaging specified.