Emerson 1000 User Manual

The UPS has a DB-9 (9 pin female) connector on the rear to allow UPS status communications with a 

computer running Liebert MultiLink software in contact closure mode. The connection provides On 

Battery and Low Battery notification.
When power is interrupted and battery power is low, Liebert MultiLink software can signal the host 

computer to gracefully shut down the operating system.

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.

When Pin 6 is shorted to Pin 5, the UPS output is shut Off no matter what mode the UPS is operating 

in. 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.

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.

Network (in and out) connectors on the rear of the UPS provide transient voltage surge suppression 

(TVSS) for network devices.

1

Low Battery (open collector)

2

UPS TxD (not used)

3

UPS RxD (not used)

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)