Keithley 2450 Reference Manual page 76

Model 2450 Interactive SourceMeter® Instrument Reference Manual
DCL
This event clears the GPIB interface. When the Model 2450 detects a device clear (DCL) event, it
does the following actions:
•
Clear the input buffer, output queue, and command queue
•
Cancel deferred commands
•
Clear any command that prevents the processing of any other device command
A DCL event does not affect instrument settings and stored data.
GTL
When the instrument detects the go to local (GTL) event, it exits remote operation and enters local
operation. When the instrument is operating locally, you can control the instrument from the front
panel.
IFC
When the instrument detects an interface clear (IFC) event, the instrument enters the talker and the
listener idle state. When the instrument is in this state, the GPIB  indicators on the front panel are
not displayed.
An IFC event does not interrupt the transfer of command messages to and from the instrument.
However, messages are suspended. If the transfer of a response message from the instrument is
suspended by an IFC event, the transfer resumes when the instrument is addressed to talk. If transfer
of a command message to the instrument is suspended by an IFC event, the rest of the message can
be sent when the instrument is addressed to listen.
LLO
When the instrument detects a local lockout (LLO) event, most of the front-panel controls are
disabled. This event disables all front-panel controls except the OUTPUT ON/OFF and POWER
switches.
To enable the front-panel, use the go to local (GTL) event.
REN
When the instrument detects the remote enable (REN) event, it is set up for remote operation. The
instrument is not placed in remote mode when it detects the REN event; the instrument must be
addressed to listen after the REN event before it goes into remote mode.
You should place the instrument into remote mode before you attempt to program it over the bus.
SDC
The selective device clear (SDC) event is similar to the device clear (DCL) event. However, the SDC
event clears the interface for an individual instrument instead of clearing the interface of all
instruments.
When the Model 2450 detects an SDC event, it will do the following for the selected instrument:
•
Clears the input buffer, output queue, and command queue
•
Cancels deferred commands
•
Clears any command that prevents the processing of any other device command
An SDC does not affect instrument settings and stored data.
2450-901-01 Rev. B/September 2013
Section 2: General operation
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