Monitors an MGE "Pulsar EXL5" UPS with a UM-Link Ethernet interface via SNMP. (Note: The probe can be used as a starting point for the design of similar probes for other models from MGE, but this implementation assumes a single phase/single receptacle unit (i.e. it only looks at the first entry in tables that index on phases or receptacles) and has only been tested on an EXL5 UPS.)