Keithley 6487 Reference Manual

Model 6487 Reference Manual Common Commands 11-5
F) TST? — self-test query Run self-test and read result
Use this query command to perform a checksum test on ROM. The command places the
coded result (0 or 1) in the output queue. When the Model 6487 is addressed to talk, the
coded result is sent from the output queue to the computer.
A returned value of zero (0) indicates that the test passed and a value of one (1) indicates
that the test failed.
G) WAI — wait-to-continue Wait until previous commands are completed
Effectively, the *WAI command is a No-Op (no operation) for the Model 6487 and thus,
does not need to be used.
Two types of device commands exist:
• Sequential commands — A command whose operations are allowed to finish
before the next command is executed.
• Overlapped commands — A command that allows the execution of subsequent
commands while device operations of the overlapped command are still in
progress.
The *WAI command is used to suspend the execution of subsequent commands until the
device operations of all previous overlapped commands are finished. The *WAI command
is not needed for sequential commands.

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%