Keithley 6487 User Manual

3-12 Measurements and Sourcing Voltage Model 6485 and 6487 User’s Manual
Programming example — ohms measurements
The following command sequence will perform one zero-corrected resistance measurement:
*RST ' Return 6487 to GPIB defaults.
FORM:ELEM READ,UNIT ' Measurement, units elements only.
SYST:ZCH ON ' Enable zero check.
RANG 2e-9 ' Select the 2nA range.
INIT ' Trigger reading to be used as zero
' correction.
SYST:ZCOR:ACQ ' Use last reading taken as zero
' correct value.
SYST:ZCOR ON ' Perform zero correction.
RANG:AUTO ON ' Enable auto current range.
SOUR:VOLT:RANG 10 ' Select 10V source range.
SOUR:VOLT 10 ' Set voltage source output to 10V.
SOUR:VOLT:ILIM 2.5e-3 ' Set current limit to 2.5mA.
SENS:OHMS ON ' Enable ohms function.
SOUR:VOLT:STAT ON ' Put voltage source in operate.
SYST:ZCH OFF ' Disable zero check.
READ? ' Trigger and return one reading.
Model 6487 voltage source operation
Configuring the voltage source
Press CONFIG then OPER to set the voltage source mode. You will first be prompted to
choose DC or SWEEP mode. (Select DC for normal operation. See Section 6 for details
on sweeps.) After the mode is selected, the disp
lay shows a full-resolution value of the
voltage source with the left-most position highlighted for editing. (If you do not wish to
change the mode, you can jump right to this voltage edit display by pressing either
V-SOURCE adjustment key). The
ß and © keys are used to select the digit being edited,
and the V-SOURCE
¹ and ƒ keys change the value. The RANGE ¹ and ƒ keys change the
voltage source range and indicate the range selected. Note that the V-SOURCE
¹ and ƒ
keys will operate in the same manner as the RANGE
¹ and ƒ keys if they are not being used
to change the voltage source value.
Voltage values are changed imm
ediately from this configuration by pressing the arrow
key. The digits will not increment beyond the maximum voltage for the selected range.
After the voltage value and range are
selected press EXIT to return to normal readings dis-
play or press ENTER to advance to the current limit display. The current limit display
offers di
fferent choices depending on the source range (refer to Table 3-6). Pressing
ENTER or EXIT from this display returns you to
the normal readings display.

Keithley 6487 Specifications

General

Type	Picoammeter/Voltage Source
Current Measurement Range	20 fA to 20 mA
Interfaces	GPIB, RS-232
Voltage Burden	< 200 µV
Input Impedance	>10^14 Ω
Power	100 V / 120 V / 220 V / 240 V
Basic Current Measurement Accuracy	0.4%