Model 6517B Electrometer Reference Manual
Section 11: Remote operations
6517B-901-01 Rev. C / August 2015
11-17
Idle and initiate
The instrument is considered to be in the idle state whenever it is not operating within one of the
layers of the trigger model. The front panel ARM indicator is off when the instrument is in the idle
state. While in the idle state, the instrument cannot perform any measure or scan functions. Over the
bus, there are two SCPI commands that can be used to take the instrument out of the idle state;
:INITiate
or
:INITiate:CONTinuous ON
.
Notice that with continuous initiation enabled (
:INIT:CONT ON
), the instrument does not remain in
the idle state after all programmed operations are completed. However, the instrument can be
returned to the idle state at any time by sending the
*RST
command, the
*RCL
command, or the
SYST:PRES
command.
Trigger model layers
As described in the previous topic, the trigger model uses three layers: Arm Layer1, Arm Layer 2, and
the trigger layer. For front panel operation, these layers are known as the arm layer, scan layer, and
measure layer.
Once the Model 6517B is taken out of the idle state, operation proceeds through the layers of the
trigger model down to the device action where a measurement occurs.
Control sources
With the one-shot trigger mode selected, a measurement (device action) does not occur until the
selected control source event is detected. The control sources are explained as follows:
Immediate: With this control source selected, event detection is immediately satisfied allowing
operation to continue. Using this selection is effectively the same as using the continuous trigger
mode.
Manual: Event detection is satisfied by pressing the
TRIG
key. Note that the Model 6517B must
be taken out of remote before it responds to the TRIG key. Pressing
LOCAL
takes the instrument
out of remote.
GPIB: Event detection is satisfied when a bus trigger (
GET
or
*TRG
) is received by the
Model 6517B.
External: Event detection is satisfied when an input trigger through the EXTERNAL TRIGGER
connector is received by the Model 6517B.
Timer: Event detection is immediately satisfied on the initial pass through the layer. Each
subsequent detection is satisfied when the programmed timer interval (1 to 999999.999 seconds)
elapses.
Control source loops
As can be seen in the flowchart, each layer has three paths that allow operation to loop around the
control source. These three paths are described as follows:
:DIRection
(Source Bypass): When a source bypass is enabled (
:DIRection SOURce
) and
the
EXTernal
or
TLINk
control source is selected, operation loops around the control source on
the initial pass through the layer. If programmed for another event detection in the layer, the
bypass loop is not in effect even though it is still enabled. The bypass loop resets (be in effect) if
operation loops back to a higher layer (or idle).
