Agilent Technologies N6700 Fault/Inhibit System Protection, Clearing a System Protection Fault

Appendix B Using the Digital Port

Fault/Inhibit System Protection

The following figure illustrates some ways that you can connect the

Fault/Inhibit pins of the connector.

FLT		INH
1	2	3	4	5	6	7	I
+	-

FLT		INH
1	2	3	4	5	6	7	I
+	-

FLT		INH
1	2	3	4	5	6	7	I
								Panic
+	-						INH	switch
							Input

INH

Common

As shown in the figure, when the Fault outputs and Inhibit inputs of several mainframes are daisy-chained, an internal fault condition in one of the mainframes will disable all of them without intervention by either the controller or external circuitry.

You can also connect the Inhibit input to a manual switch or external control signal that will short the Inhibit pin to common whenever it is necessary to disable all output channels in the mainframe. Negative polarity must be programmed for all pins in this case. You can also use the Fault output to drive an external relay circuit or signal other devices whenever a user-definable fault occurs.

Clearing a System Protection Fault

To restore all instruments to a normal operating condition when a fault condition occurs in a daisy-chained system protection configuration, two fault conditions must be removed:

1. The initial protection fault or external Inhibit signal.

2. The subsequent daisy-chained fault signal (which is sourced by the Inhibit signal).

		Even when the initial fault condition or external signal is removed, the Inhibit
	NOTE
		fault signal is still active and will continue to shut down the outputs of all the
		mainframes.
		To clear the daisy-chained fault signal if the operating mode of the
		Inhibit input is Live, simply clear the output protection on any ONE
		mainframe as explained in chapter 4. If the operating mode of the
		Inhibit input is Latched, turn off the Inhibit input on ALL mainframes
		individually. To re-enable the chain, re-program the Inhibit input on
		each mainframe to Latched mode.
Output State
		Only pins 4 through 7 can be configured to control the output state.
		This function lets you connect multiple Agilent N6700 mainframes
		together and synchronize the output on/off sequence across
		mainframes. Refer to Appendix D for detailed information.

94 Series N6700 User’s Guide