modbus

Modbus interface

This interface starts a modbus TCP connection and retrieves register information for publishing via mqtt to emonCMS For a FRONIUS Inverter specific config to log inver model/brand/software versions on init to the log file change the Type setting to EmonFroniusModbusTcpInterfacer

Usage and configuration

There is a sample modbusTCP.emonhub.conf file located in this directory. The rType and datacodes must match. Use the table below to assist.

Sample interfacer config within emonhub.conf

Sample configuration for modbus TCP clients

    [[ModbusTCP]]
        # this interfacer retrieves register information from modbusTCP clients
        # retrieve register information from modbus TCP documentation for your inverter.
        Type = EmonModbusTcpInterfacer
        [[[init_settings]]]
            modbus_IP = 192.168.1.10   # ip address of client to retrieve data from
            modbus_port = 502          # Portclient listens on
        [[[runtimesettings]]]
            # List of starting registers for items listed above
            register = 40118,40092,40102,502,40285,40305,40284,40304,40086,40088,40090
            # nodeid used to match with node definition in nodes section below. Can be set to any integer value not previously used.
            nodeId = 12
            # Channel to publish data to should leave as ToEmonCMS
            pubchannels = ToEmonCMS,
            # time in seconds between checks, This is in addition to emonhub_interfacer.run() sleep time of .01
            # use this value to set the frequency of data retrieval from modbus client
            interval = 10

The default unit or slave number is 1. To query registers from different slaves, add a nUnit key, and specify as many numbers as there are registers to query.

[[[runtimesettings]]]
    register = 305, 306, 314, 321, 0xA001
    # unit number for each Register
    nUnit = 2, 2, 2, 2, 3

Sample Node declaration in emonhub.conf

Node ID must match node ID set in interfacer definition above

    [[12]]
        nodename = fronius
        [[[rx]]]
            # list of names of items being retrieved
            # This example retrieves the Inverter status, AC power in watts being produced, AC Lifetime KWh produced,
            # KWh produced for current day,....
            names = Inverter_status,AC_power_watts,AC_LifetimekWh,DayWh,mppt1,mppt2,Vmppt1,Vmppt2,PhVphA,PhVphB,PhVphC
            datacodes = H,f,f,Q,H,H,H,H,f,f,f
            scales = 1,0.1,0.1,1,1,1,1,1,0.1,0.1,0.1
            units = V,W,kWh,Wh,W,W,V,V,V,V,V