Digital I/O Port, Interlock, and Output Configuration 12-9
GUARD
With this output-off state, the current source is selected and set to 0A. Voltage compliance is
set to 0.5% full scale of the present voltage range. This output-off state should be used when
performing 6-wire guarded ohms measurements or for any other load that uses an active
source.
NOTE When changing the output-off state with the output off, the selected output-off state
will be entered immediately.
Output off states and inductive loads
The output off state you select for inductive loads depends on how much energy the inductor
holds. The Normal output off state is not recommended as it lowers the compliance setting. The
Zero or the Guard state are better suited, as Zero does not change the compliance setting and
the Guard output off state would change the voltage source to a current source with a voltage
compliance. The Guard state is typically used only for guarded ohms measurements.
To protect the unit from inductive energy, the application may require a spark gap across the
INPUT HI and LO terminals. The SourceMeter does not have internal spark gap protection, as
some leakage current (nA) is associated with the protection circuits.
Remote output configuration
Output configuration commands
Table 12-2 summarizes output configuration commands. These commands include those to
enable and disable the interlock as well as commands to control output off states. See Section
17, OUTPut subsystem and SOURce subsystem for more information.
Table 12-2
Output configuration commands
Command Description
:OUTPut:INTerlock:STATe <state>
:OUTPut:INTerlock:TRIPped?
:OUTPut:SMODe <name>
:SOURce:CLEar
:SOURce:CLEar:AUTO <state>
:SOURce:CLEar:AUTO:MODE <name>
Enable/disable interlock (state = ON or OFF).
Query interlock tripped state (1 = tripped).
Select output-off mode (state = NORMal, ZERO, or GUARd).
Turn output source off when in idle state.
Enable/disable auto output-off. State = ON (output off after
measurement) or ON (output stays on).
Auto clear mode. Name = ALWays (every reading; default) or
TCOunt (ON when trigger layer entered; OFF when leaving
trigger layer).