Ablerex KRONOS Installation And Operation Manual page 45

 SW2
When the Relay Card is installed in Slot 2, move the switch to "Slot" position.
When SNMP card is installed in Slot 2, move the switch to "SNMP" position.
 SW3--the switch for terminal resistor of parallel communication
To ensure a proper parallel communication connection, the selector switch on each of the
additional UPSs', starting from the furthest UPS, must be moved to the "ON" position.
Please refer to section 2-7 for detail.
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