Location Of Ups Configuration Switches - IBM 4800-741 Hardware Service Manual

Updated July 14, 2008
Configuration switches
The DIP switches are located on the front panel of the UPS subassembly (see A
in Figure 9). These switches allow you to select whether the ON or OFF state of the
connected system unit controls the operation of the UPS during an AC power
outage.
Standalone mode: When both switches are set to the OFF or the up position
(factory default), the UPS always enters battery mode during an AC outage. The
unit remains in battery mode until AC is restored or until the battery is discharged.
On-battery and low-battery signals are available to the associated system when an
RS-232 cable connection is in place, but there is no control of the UPS from the
system unit. This mode of operation is typical for the standby type of power
supplies commonly found in the marketplace.
Host-dependent mode: The host-dependent mode is when both DIP switches are
set in the ON or down position. During an AC outage, the UPS does not remain in
battery mode for more than five seconds unless there is an active RS-232
connection present from a powered-on system unit. If the system unit is powered
on, the UPS remains in standby mode. If the system unit is powered off, the unit
does not stay in standby mode. When AC power is restored, AC power is again
available at the UPS output. This setting is useful for situations where systems units
are powered down at the close of business and the main store power is also shut
down. This setting prevents the UPS from switching into standby mode and
discharging the battery when the store power is removed.
A
Figure 9. Location of UPS configuration switches
11
Chapter 1. Introducing the SurePOS 700 Models