Keithley 6487 Reference Manual

3-10 Measurements and Sourcing Voltage Model 6487 Reference Manual
SCPI programming
A) SENSe:DATA?
This command does not trigger a reading. It simply returns the last “raw” reading string. It
will not return the result of any instrument calculation. The reading reflects what is
applied to the input.
While Model 6487 is busy performing measurements, the :DATA? command will not
return the reading string until the instrument finishes and goes into the idle state.
klqb The format that the reading string is returned in is set by commands in
Section 13.
If there is no reading available when :DATA? is sent, an error (-230) will occur.
B) FUNCtion ‘CURRent’
Use this command to select the current function instead of the ohms function.
C) INITiate
To return a fresh (new) reading, you can send the INITiate command to trigger one or
more readings before sending :DATA?. Details on INITiate are provided in Section 7.
D) READ?
The READ? command can be used to return “fresh” readings. This command triggers and
returns the readings. See Section 12 for details.
Table 3-5
SCPI commands — amps function
Commands Description Default Ref
[SENSe]
:DATA?
:FUNCtion ‘CURRent’
INITiate
READ?
SENSe Subystem:
Return latest “raw” reading.
Select current function.
Trigger one or more readings.
Trigger and return reading(s).
CURR
A
B
C
D

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%