Negligible Participation Metric

    node-red-contrib-modbustcp

    1.2.3 • Public • Published

    node-red-contrib-modbustcp

    NPM

    Node-Red Modbus TCP nodes for communicating with a Modbus TCP server.

    Based on jsmodbus.

    Install

    Run the following command in the root directory of your Node-RED install

    npm install node-red-contrib-modbustcp
    

    Nodes

    modbus read

    alt tag

    API

    In addition, you can pass in a msg with one or more payload settings to initiate additional modbus read events.

    msg.payload = {
        "name": "Name1", // Should be a unique name
        "topic": "topic1", // Override default topic 
        "dataType": "FC3", // can be format 3, "FC3", or "Coil"
        "address": 0, // starting address
        "quantity": 4, // # of units to read
        "interval": 3000, // polling interval in milliseconds
        "ieeeType": "off", // valid values are "off", "single" or "double"
        "ieeeBE": true // Big Endian format, true/false. false = little endian
    }

    Most of the values are optional and server to override the defaults set in the nodes config.

    Values for dataType inlcude:

    • "Coil", "FC1", "FC 1", 1
    • "Input", "FC2", "FC 2", 2
    • "HoldingRegister", "FC3", "FC 3", 3
    • "InputRegister", "FC4", "FC 4", 4

    If you pass in a msg with a payload.name that is the same as one previously passed in, the new values will replace the old. For example, it is possible to change the polling interval of an existing event by passing in the same msg structure with a different "interval" setting.

    Note: The IEEE 754 formatting is not applied to binary data types such as "Coil" and will be ignored for those.

    Note: Setting ieeeBE = false will for the node to read the inputs as "little endian".

    Stop/Kill You can stop or kill the polling of a modbus item by passing in the following:

    alt tag

    The polled event with the same name given will be stopped if the kill=true is also passed in.

    example single input

    alt tag

    example multiple input

    alt tag

    modbus write

    alt tag

    API

    In addition to passing in a payload value for writing, you can also pass in the following in your msg to override the configured defaults:

    • dataType
      • "Coil", "FC5", "FC 5", 5
      • "HoldingRegister", "FC6", "FC 6", 6
      • "Coils", "FC15" "FC 15", 15
      • "HoldingRegisters", "FC16", "FC 16", 16
    • address

    example message input:

    msg = {
        address: 8,
        dataType: "Coil",
        payload: 1
    }

    Author

    Install

    npm i node-red-contrib-modbustcp

    DownloadsWeekly Downloads

    170

    Version

    1.2.3

    License

    BSD-3-Clause

    Unpacked Size

    138 kB

    Total Files

    13

    Last publish

    Collaborators

    • jayharper