Specifications

108 Chapter 5

Measurement Start and Detection of Measurement End

Measurement Trigger (Measurement Start)

Trigger System

The E4991A trigger system has three states: “Idle,” “Waiting for trigger,” and

“Measuring.” as shown in

Figure 5-1.

Figure 5-1 Trigger System

The following section explains the state transitions of the trigger system.

Idle State

Immediately after the E4991A is powered on, the trigger system is in the Idle state.

However, the trigger system soon transits to the Waiting for trigger state because the

trigger system’s continuous initiation feature is enabled and the trigger source is set to

internal trigger. After that, the E4991A transits between the Measuring and Waiting for

trigger states. Also, when one of the following GPIB commands is executed, the trigger

system transits to the Idle state.

• *RST on page 282

• ABOR on page 286

When the dc bias function has been switched from disabled to enabled, the trigger system

transits to the Idle state.

If the trigger system has been initiated using the following GPIB command, the state

changes from Idle to Waiting for trigger.

• INIT on page 382

• INIT:CONT on page 382