30   Chapter 9    Communication 
Chapter 9   Communication 
This chapter introduces communication of the Liebert® GXT4™ UPS, including communication interface port, 
terminal block, Liebert IntelliSlot® communication cards and remote emergency power off. 
9.1   Communication Interface Port 
The Liebert® GXT4™ UPS has a terminal block on the rear of the UPS unit. Several signals are provided on this port 
and are assigned as follows. 
9.2   Terminal Block 
The terminal block includes eight pins, as shown in Figure 9-1. 
 
Figure 9-1 Terminal block communication pin layout 
9.2.1   Any-Mode Shutdown 
The purpose of Any Mode Shutdown is to shut down the UPS output by turning Off the rectifier, inverter and static 
switch so that there is no power to the loads. 
Any Mode Shutdown can be operated locally or remotely: 
 Local Any Mode Shutdown can be performed by shorting the pins in Set 3. 
 Remote Any Mode Shutdown can be performed using a switch connected to the pins in Set 3 and mounted at a 
remote location. 
Activation of the Any Mode Shutdown will be logged as an event in the event history log. 
  Note 
Remote Power Off will be performed either by NO or NC contact of Any Mode Shutdown. The current limited source for the 
optocoupler (+12VDC, 50mA) will be available from UPS. The connection to UPS for remote connection will be via terminal 
block connector. Any Mode Shutdown wiring must conform to all national, regional and local wiring codes and laws. 
 
  Warning 
When the Auto-enable output option is selected and the UPS output is disabled using the pins in Set 3, the Liebert GXT4’s output 
can turn On automatically and without warning if the connection of the pins in Set 3 is changed. 
 
9.2.2   Battery Mode Shutdown 
Battery Mode Shutdown permits shutting down the UPS by turning off the rectifier, inverter and static switch so that 
there is no power to the load when the UPS is On Battery. The auxiliary power for the UPS will still be active. 
Battery Mode Shutdown can be performed locally or remotely: 
 Local Battery Mode shutdown can be performed by shorting the pins in Set 4. 
 Remote Battery Mode Shutdown can be performed using a switch connected to the pins in Set 4 and mounted 
at remote location. 
Liebert GXT4 UPS 5000VA ~ 10000VA (230V)  User Manual