Model 6487 Reference Manual
Triggering
7-5
Trigger model operation
Once the instrument is taken out of idle, operation proceeds through the trigger model to
perform a measurement (measure action).
klqb
The following discussion focuses on the front panel trigger model (
).
However, equivalent SCPI commands are included where appropriate.
Event detectors and control sources
A control source holds up operation until the programmed event occurs and is detected.
Note that there are two detector bypasses. A bypass around a detector is only enabled if the
appropriate TLink control source is selected. See TLink control source (Arm-In and Trig-
ger-In) as follows for details.
Arm-In source
— The Arm-In control sources are explained as follows:
•
Immediate
(ARM:SOURce IMMediate) — Event detection for the arm layer is
satisfied immediately allowing operation to continue into the trigger layer.
•
GPIB
(ARM:SOURce BUS) — Event detection for the arm layer is satisfied when
a bus trigger (GET or *TRG) is received by the Model 6487.
•
Timer
(ARM:SOURce TIMer) — Event detection for the arm layer is immediately
satisfied after the instrument leaves the idle state. Detection for each subsequent
pass is satisfied when the programmed timer interval elapses. The timer resets to its
initial state when the instrument goes back into idle.
•
Manual
(ARM:SOURce MANual) — Event detection for the arm layer is satisfied
by pressing the TRIG key. The Model 6487 must be in the local mode for it to
respond to the TRIG key. Press LOCAL or send LOCAL 14 over the bus to place
the Model 6487 in local.
•
TLink
(ARM:SOURce TLINk) — Event detection for the arm layer is satisfied
when an input trigger via the TRIGGER LINK connector is received by the
Model 6487. Note that if the source bypass is set to ONCE (ARM:DIRection
SOURce), operation will initially loop around the source detector after the instru-
ment leaves the idle state. Detection for each subsequent pass is satisfied by an
input trigger. The bypass resets when the instrument goes into idle.
•
/STest
(ARM:SOURce NSTest) — Event detection for the arm layer is satisfied
when a negative-going pulse (via the SOT line of the Digital I/O) is received from a
component handler (see
in
•
STest
(ARM:SOURce PSTest) — Event detection for the arm layer is satisfied
when a positive-going pulse (via the SOT line of the Digital I/O) is received from a
component handler (see
in
•
BSTest
(ARM:SOURce BSTest) — Event detection for the arm layer is satisfied
when either a positive-going or a negative-going pulse (via the SOT line of the Dig-
ital I/O) is received from a component handler (see
).
