Vertiv Liebert PSI XR 1000, User Manual

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6 COMMUNICATION
6.1 DB-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 shutdown software. The connection provides serial communication, On Battery
and Low Battery signals. Liebert shutdown software and a 1.8m (6 ft.) DB-9 serial cable are shipped with
the UPS.
When power is interrupted and battery power is low, Liebert shutdown software can signal the host
computer to gracefully shut down the operating system.
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 Mains Fail (open emitter)
9 Mains Fail (open collector)
Table 6.1 DB-9 pin assignment
Pin Assignment Collector to Emitter*
(-)
(+)
330 Ohms
Open
Collector
Open
Emitter
6.2 Remote 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.
6.2.1 Any 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 operating. 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 Test button.
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