Text preview for : Interlock_6487.pdf part of Keithley Interlock 6487 Keithley 6487 Interlock_6487.pdf
Back to : Interlock_6487.pdf | Home
A GREATER MEASURE OF CONFIDENCE
Product(s)
Picoammeter: 6487
Question: Why do I get a "CLOSE INTLCK" error when trying to turn ON the
source?
Answer: Model 6487 has 3 voltage source ranges: 10V, 50V, and 500V. The default
power up sequence enables the 10V source range. On this range you should never see
"CLOSE INTLCK " error on turning the OPERATE ON.
On the 50V and 500V ranges you could possibly see "CLOSE INTLCK" error when
turning the OPERATE ON. The Interlock prevents the voltage source being operated on
the 50V and 500V range, to help assure Safe operation. The Interlock is always
operational on these source ranges.
The sole purpose of this is to prevent any contact with the live circuitry when making
measurements if using a Test Fixture with a lid. A normally open switch is connected to
pins 1 and 2 of the connector as shown. When the switch is OPEN, Interlock is asserted
and voltage source cannot be placed in OPERATE on the 50 V and 500 V source
ranges, hence you get the error " CLOSE INTLOCK". When the lid is closed, this shorts
pins 1 and 2, allowing you to source voltages.
The model 6487 is shipped with a standard CS-459 connector mounted on the Interlock
I/P connector. The CS-459 shorts pins 1 and 2.
If not using a Test Fixture, make sure the CS-459 connector is mounted on the Interlock
I/P Connector. Otherwise, when you try to turn the output ON (50 or 500 volt range) the
Instrument will give a "CLOSE INTLCK" error.