Output-Off States - Keithley 6430 Instruction Manual

12-8 Digital I/O Port, Interlock, and Output Configuration

Output-off states

NORMAL
When in this relatively high-impedance output-off state, the V-Source is selected and set to
0V. Current compliance is set to 0.5% full scale of the present current range. In theory, with the
V-Source set to zero, the SourceMeter will not source or sink power. In practice, the source
value may not be exactly at zero. Therefore, the SourceMeter may source or sink a very small
amount of power. In most cases, this source or sink power level is not significant.
ZERO
When in this output-off state, the "ZER" message is displayed (instead of "OFF"), and the
SourceMeter is configured as follows:
When the V-Source is the selected source:
•
•
•
•
When the I-Source is the selected source:
•
•
•
•
While in the ZERO output-off state, the SourceMeter can be used as an I-Meter.
The ZERO output-off state can also be used with the V-Source and Output Auto-Off to gen-
erate very quick pulsed voltage waveforms. For example, with Output Auto-Off enabled, you
can generate 0 to +5V pulses. While in this relatively low-impedance output-off state, the
Source-Meter will be able to quickly dissipate (sink) current caused by high input capacitance
(i.e., cable capacitance) or an external source. This results in fast settling time. If you instead
used the NORMAL output-off state for this application, current would dissipate very slowly
(slow settling time) resulting in distorted pulses.
WARNING
The programmed V-Source value remains on the display.
Internally, the V-Source is set to 0V.
The current compliance setting remains the same as the output-on value. "Real" and
"range" compliance detection remains active.
Measurements are performed and displayed.
The programmed I-Source value remains on the display.
Internally, the V-Source is selected and set to 0V.
Current compliance is set to the programmed Source I value or to 0.5% full scale of the
present current range, whichever is greater.
Measurements are performed and displayed.
Hazardous voltages (30V rms) can appear on the selected INPUT/OUT-
PUT LO terminal when generating quick, pulsed waveforms using the
ZERO AUTO-OFF output state. To eliminate this shock hazard, connect
the LO terminal to earth ground. If using the front panel terminals, ground
the front panel LO terminal. If using the rear panel terminals, ground the
rear panel LO terminal. The ground connection can be made at the chassis
ground screw on the rear panel or to a known safety earth ground.