Forcex - Keithley 4200A-SCS Reference Manual

Model 4200A-SCS Parameter Analyzer Reference Manual

forceX

This command programs a sourcing instrument to generate a voltage or current at a specific level.
Usage
int forcei(int instr_id, double value);
int forcev(int instr_id, double value);
instr_id
value
Details
The forcev and forcei commands generate either a positive or negative voltage, as directed by
the sign of the value argument. With both forcev and forcei commands:
•
Positive values generate positive voltage or current from the high terminal of the source relative
to the low terminal.
•
Negative values generate negative voltage or current from the high terminal of the source relative
to the low terminal.
The forcev command accepts both CMTR1H and CMTR1L for the instr_id parameter to support
differential CVU biasing. By forcing one polarity on CMTR1H and an opposite polarity on CMTR1L,
total bias can be up to 60 V, centered in relationship to ground. Note that it is not possible to exceed ±
30 V in relationship to ground.
When using the limitX, rangeX, and forceX commands on the same source at the same time in a
test sequence, call the limitX and rangeX commands before the forceX command. See
Compliance limits
The ranges of currents and voltages available from a voltage or current source vary with the
instrument type. For more detailed information, refer to the hardware manual for each instrument.
To force zero current with a higher voltage limit than the 20 V default, include one of the following
calls ahead of the forcei call:
•
A measv call, which causes the 4200A-SCS to autorange to a higher voltage limit.
•
A rangev call to an appropriate fixed voltage, which results in a fixed voltage limit.
To force zero volts with a higher current limit than the 10 mA default, include one of the following calls
ahead of the forcev call:
•
A measi call, which causes the 4200A-SCS to autorange to a higher current limit.
•
A rangei call to an appropriate fixed current, which results in a fixed current limit.
Note that changing the source mode of the SMU can modify the measure range. If the sourcing mode
is changed from voltage to current sourcing (or from current to voltage sourcing), the measure range
may be changed to minimize variations in the SMU output level. See
recommended command order.
4200A-901-01 Rev. C / February 2017
The instrument identification code
The level of the bipolar voltage or current forced in volts or amperes
(on page 3-3) for details.
Section 13: LPT library function reference
rangeX (on page 13-83) for
13-69