Engaging Hardware Interlocks; Interlock Status; Figure 9-2: Slot[X].Interlock.state Icl Command - Keithley 3700 Series User Manual

Series 3700 System Switch/Multimeter User's Manual

Engaging hardware interlocks

To engage the hardware interlocks, you must provide a low resistance path
between the two applicable interlock pins as shown in the diagram. This path
routes a 5 V power source to an onboard interlock relay which in turn enables
power to the backplane relays. If a 37xx-ST accessory terminal board is used,
this low resistance path is provided to automatically engage the interlock circuit.
NOTE

Interlock status

Some switching modules have more than one interlock. At any time, the current
status of each interlock can be determined by using the appropriate ICL
command shown below. When the interlock status reports engaged, associated
backplane relays are allowed to be energized. When the interlock status reports
disengaged, associated backplane relays are prevented from being energized.

Figure 9-2: slot[X].interlock.state ICL command

3700S-900-01 Rev. C / July 2008
Do not use the supplied 5 V power source for anything other than
energizing the interlock relay. It is not designed for external circuit
use.
Be sure to provide a low resistance path between the interlock pins for
reliable operation. Significant resistance if present can cause the
interlock circuit to fail to engage.
Section 9: Series 3700 Module Schematics and Connections
9-11