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6482-901-01 Rev. A / August 2012
Section 8: Triggering
Model 6482 Dual-Channel Picoammeter / Voltage Source Reference Manual
Remote operation of the trigger model
Trigger model
The trigger model flow chart in
summarizes remote trigger operation. Operation is
controlled by SCPI commands from the trigger subsystem. Key remote commands are included in
the trigger model. Also note that the GPIB defaults are denoted by the “
+
” symbol.
The primary actions of the trigger model are source, delay, and measure. The source action
outputs the programmed voltage or current value, and the programmed delay provides a settling
period for the source before the measurement is performed.
The trigger model consists of two layers (Arm layer and Trigger layer) to provide versatility.
Programmable counters allow operations to be repeated, and various input and output trigger
options are available to provide source-measure synchronization between the Model 6482 and
other instruments (using the trigger link).
Idle and initiate
The instrument is considered to be in the idle state (ARM indicator off) when it is not operating
within the trigger model layers. While in the idle state, the instrument cannot perform any
measurements. An initiate command is required to take the instrument out of an idle state. The
following commands perform an initiate operation:
•
:INITiate
•
:READ?
•
:MEASure?
Conversely, if the instrument is taking readings, most commands (except DCL, SDC, IFC, and
ABORt) are queued and will not be executed until the instrument returns to the idle state.
The :MEASure? command will automatically turn the output on. Note that after the instrument
returns to the idle state, the output will remain on.
When automatic output-off is enabled (:SOURce[1]1:CLEar:AUTO ON or :SOURce2:CLEar:AUTO
ON), any of the three commands can be used to initiate operation (:INITiat, :READ?, or
:MEASure?). The source output will automatically turn on at the beginning of each source-delay-
measure (SDM) cycle and turn off after each measurement is completed.
While operating within the trigger model (ARM indicator on), most commands will not be executed
until the Model 6482 completes all of its programmed source-measure operations and returns to
the idle state. The IFC (interface clear), SDC (selected device clear) and DCL (device clear)
commands can be executed under any circumstance while operating within the trigger model. The
following commands will abort any other command or query.
•
:ABORt
•
:SYSTem:PRESet
•
*TRG or GET
•
*RST
•
*RCL
NOTE
SDC, DCL, or :ABORt place the Model 6482 in the idle state. For fastest response, use
SDC or DCL to return to the idle state.
Summary of Contents for 6482
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