Keysight Technologies RP7900 Series, Operating And Service Manual

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illuminated blue switch that is located remotely, which indicates a reset is required when lit. An
additional blue RESET lamp is also located on the SDS front panel. The RESET signals are located on
the Remote Interface connector on the SDS rear panel.
The operation of the Reset lamps is defined as follows:
l
Turns on when an ESTOP switch closes
l
Turns on when an error condition occurs (loss of power, loss of communication, etc.)
l
Turns off when ESTOP button is released and SDS and power supply are reset
Customer-supplied Fixture Cover Switches
If a fixture cover is not being used, you must short Fixture Cover pin 1 to pin 2 and pin
3 to pin 4. If the pins are not shorted, there will be a SDP protection event - requiring
power cycling.
Fixture cover switches must be dual-channel, normally-open switches that are mechanically
interlocked to a safety cover. This safety cover must limit access to the UUT during normal operation.
The fixture cover input is a non-resetting input. When the fixture cover is opened allowing access to
the UUT, the fixture cover switches open - initiating a disconnect sequence. When the fixture cover is
closed all switches close, returning the SDS to the previous state. The fixture cover signals are
located on the Fixture Cover connector on the SDS rear panel.
The operating sequence of the SDS in response to an open fixture cover input is as follows:
1. Opens the power relays
2. Opens the sense relays
3. Disables the power supply output
4. Discharges the UUT
5. Returns the SDS and power supply to the prior state when the cover is closed
The SDS remains in the safe state as long as the fixture cover input is true (open). When the fixture
cover is open, the power supply indicates a status of Inhibit (INH). A SCPI query can be used to
determine the cause of the power supply inhibit.
Customer-supplied AC Contactor
If an AC contactor is not being used, you must short DI/DO pin 3 to pin 4. If the pins
are not shorted, there will be a SDP protection event - requiring power cycling.
A programmable general purpose output, +24V (DOutput-1) with a return (DOutput-2), is available on
the DI/DO connector on the SDS rear panel to control the relay coil of an external AC contactor.
Normally-closed auxiliary contacts from the AC contactor should also be wired to DInput-3 and
DInput-4 to sense the state of the AC contactor. The DInput-DOutput combination form a safety
handshake with the AC contactor.
Appendix A Keysight SD1000A Safety Disconnect System
312 Keysight RP7900 Series Operating and Service Guide