Modbus TCP
Fenecon MasterBox2V0 Relay
Fenecon
Overview
The Fenecon MasterBox2V0 Relay is a six-channel digital I/O relay module integrated into the FENECON Energy Management System (FEMS). It is used to switch external loads such as SG-Ready heat pumps, heating elements, combined heat and power units, and other consumers based on energy management signals. This template reads the live status of all six relay channels via Modbus TCP (addresses 105 to 110) and writes switch commands to the corresponding setpoint registers (addresses 1 to 6). Monitoring actual relay states alongside commanded states lets you verify correct switching in real time.
Use cases
- Monitor all six relay status registers to verify that SG-Ready heat pump switching commands are executed correctly.
- Compare relay_1_a through relay_6_a read-back values against issued commands to detect contact failures or wiring faults.
- Alert on unexpected relay state changes outside scheduled time windows to spot unwanted activation of connected loads.
- Track relay switching frequency over time to identify excessive on/off cycles that may shorten contactor life.
