Liebert PSP C

COMMUNICATIONS

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

status communications with a computer system running MultiLink™

software. The DB-9 is capable of supplying serial communication, on

battery and low battery signals. MultiLink, Liebert’s UPS monitoring

and shutdown software, is shipped with the UPS, along with a 10-ft.

(3m) DB-9 cable required for running MultiLink.

When MultiLink is installed on the host computer, the UPS can signal

“on battery” and “low battery” using opto-couplers. When the UPS is

operating in Battery mode, it can receive a signal from the host com-

puter system that will shut down the UPS (after gracefully shutting

down the operating system on the host computer system) when the

remaining battery run time is low. The timing of the signal depends

on MultiLink’s configuration settings. This shutdown signal

(5-12VDC) must have a duration of at least 2 seconds for the UPS to

be shut down. The UPS communicates via serial communications

using Liebert ESP II protocol.

* Maximum voltage and current on Pins 1, 7, 8, and 9 is 55VDC; 10.0 mA.

DB-9 Pin Assignment Description

1 Low Battery (open collector)

2 UPS TxD (typical RS-232 levels)

3 UPS RxD (typical RS-232 levels)

4 Battery Mode Shutdown (5-12VDC, 10-24 mA max)

5 Common

6 Any Mode Shutdown (short to Pin 5)

7 Low Battery (open emitter)

8 Utility Fail (open emitter)

9 Utility Fail (open collector)

DB-9 Pin Assignment Collector to Emitter*

54321

6789 (+) Open

Collector

(-) Open

Emitter