Справочник Пользователя для Liebert POWER PROTECTION STATIC TRANSFER SWITCH

The optional Programmable Relay Board (PRB) has eight channels to report events to an external 

device. Up to ten (10) events can be programmed to each channel. See 6.1 - Programmable Relay 

Board for more information on the PRB.
If your STS2 has the PRB option installed, list the settings below for future reference. If control power 

is lost in the STS2, the settings are not saved.