Liebert PSI XR Remote Shutdown Via the DB-9 Connector, Communication, DB-9 pin assignment

Communication

6.0COMMUNICATION

6.1DB-9 Connector

The UPS has a DB-9 (9 pin female) connector on the rear to allow UPS status communications with a computer running Liebert MultiLink shutdown software. The connection provides serial communica- tion, On Battery and Low Battery signals. Liebert MultiLink software and a 6 ft. (1.8m) DB-9 serial cable are shipped with the UPS.

When power is interrupted and battery power is low, Liebert MultiLink software can signal the host computer to gracefully shut down the operating system.

Table 4	DB-9 pin assignment
DB-9 Pin					Assignment Description
1			Low Battery (open collector)
2			UPS TxD
3			UPS RxD
4			Remote Shutdown (5-12V); on-battery operation
5			Common
6			Output Off, (short to Pin 5, non-latching); any mode operation
7			Low Battery (open emitter)
8			Utility Fail (open emitter)
9			Utility Fail (open collector)
	Pin Assignment				Collector to Emitter*
	6	7	8	9		(+)	Open
							Collector
					330 Ohms
1	2	3	4	5		(-)	Open
							Emitter

6.2Remote Shutdown Via the DB-9 Connector

The Liebert PSI XR can be shut down remotely by shorting Pins 5 and 6 or via Pins 4 and 5 of the DB-

9 connector.

6.2.1Any Mode Shutdown Via Pins 5 & 6

When Pin 6 is shorted to Pin 5, the UPS output is shut Off no matter what mode the UPS is operat- ing. The UPS cannot be started as long as the pins are shorted. When the short is removed, the UPS output can be enabled by pressing the ON/Alarm Silence/Manual Self-Diagnostic button.

6.2.2Battery Mode Shutdown Via Pins 4 & 5

While the UPS is operating on battery, a 5-12VDC signal for 2 seconds or longer is required to signal a shutdown. Signals for less than 2 seconds are ignored.

After Pin 4 receives the shutdown signal, a 2-minute shutdown timer begins a countdown. The shut- down timer cannot be stopped: If utility power returns during the 2-minute countdown, the shutdown timer continues until the end of 2 minutes and the UPS turns Off. The UPS will restart 10 seconds after utility power returns.

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