Keithley 6512, Instruction Manual

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IEEE-488 Programming
3-15
3.2.12 Trigger mode (T)
Purpose
To control the source that triggers readings as well as whether the instrument operates in the con-
tinuous or one-shot trigger mode.
Format
T0 Continuous Mode, Triggered by Talk
T1 One-shot Mode, Triggered by Talk
T2 Continuous Mode, Triggered by GET
T3 One-shot Mode, Triggered by GET
T4 Continuous Mode, Triggered by X
T5 One-shot Mode, Triggered by X
T6 Continuous Mode, Triggered with External Trigger
T7 One-shot Mode, Triggered with External Trigger
Default
Upon power-up, or after the instrument receives a DCL or SDC command, the T6 (continuous
mode, external trigger) mode will be enabled.
Description
Triggering provides a stimulus to begin a reading conversion within the instrument. Triggering
may be done in two basic ways: in a continuous trigger mode, a single trigger stimulus is used
to restart a continuous series of readings. In a one-shot mode, a single reading will be processed
each time the appropriate trigger stimulus is given.
The trigger modes are paired according to the type of stimulus that is used to trigger the instru-
ment. In the T0 and T1 modes, triggering is performed by addressing the Model 6512 to talk. In
the T2 and T3 modes, the IEEE-488 multiline GET command performs the trigger function. The
instrument execute (X) character provides the trigger stimulus in the T4 and T5 modes, while a
trigger pulse applied to the rear panel EXTERNAL TRIGGER INPUT, triggers the instrument
in the T6 and T7 modes.
Programming 1. A trigger stimulus will abort the present reading conversion and immediately begin another.
Notes
2. The front panel TRIG button will trigger the instrument regardless of the selected trigger
mode, unless LLO is in effect.
3. Serial polling addresses the instrument to talk. This talk command will trigger the instru-
ment in the T0 and T1 modes.