Keithley 6485 User Manual

9-8 Remote Operation Model 6485 Picoammeter Instruction Manual
Note that all front panel controls, except for LOCAL and POWER, are inoperative while
the instrument is in remote. You can restore normal front panel operation by pressing the
LOCAL key.
IFC (interface clear)
The IFC command is sent by the controller to place all instruments on the bus in the local,
talker, listener idle states. Model 6485 responds to the IFC command by canceling front
panel TALK or LSTN lights, if the instrument was previously placed in one of those states.
Note that this command does not affect the status of the instrument; settings, data, and
event registers are not changed.
To send the IFC command, the controller must set the IFC line true for a minimum of
100µs.
LLO (local lockout)
Use the LLO command to prevent local operation of the instrument. After the unit receives
LLO, all its front panel controls except the POWER are inoperative. In this state, pressing
LOCAL will not restore control to the front panel. The GTL command restores control to
the front panel.
GTL (go to local)
Use the GTL command to put a remote mode instrument into local mode. The GTL com-
mand also restores front panel key operation.
DCL (device clear)
Use the DCL command to clear the GPIB interface and return it to a known state. Note
that the DCL command is not an addressed command, so all instruments equipped to
implement DCL will do so simultaneously.
When Model 6485 receives a DCL command, it clears the input buffer and output queue,
cancels deferred commands, and clears any command that prevents the processing of any
other device command. A DCL does not affect instrument settings and stored data.
SDC (selective device clear)
The SDC command is an addressed command that performs essentially the same function
as the DCL command. However, since each device must be individually addressed, the
SDC command provides a method to clear only selected instruments instead of clearing all
instruments simultaneously, as is the case with DCL.

Keithley 6485 Specifications

General

Model	Keithley 6485
Category	Picoammeter
Input Impedance	>10^14 Ohms
Voltage Burden	<200µV
Accuracy	0.4% of reading
Voltage Source Range	Not Applicable
Voltage Source Resolution	Not Applicable
Voltage Source Accuracy	Not Applicable
Interface	IEEE-488
Power Requirements	100V to 240V AC, 50/60Hz
Dimensions	89 mm high x 214 mm wide x 369 mm deep (3.5 in x 8.4 in x 14.5 in)