ModBus: How to Write 32bits data

Industrial
1

Hello,

I need to send a string of information to a Modbus device; They can be numbers from 1000 (decimal) to 120000, so the device receives 32 bits of information for each DWORD.

I have tried with Modbus TCP Node and with the one I am most interested in using the Modbus Flex-Write Node.

In neither of the two, I get it to send the value to the device correctly, if this value is greater than 65535. If it is less than this value, there is no error.

These are the examples I try to use, but none of them have worked for me with values greater than 65535...

Can you help me, please?

    {
        "id": "35e959d48dc8655d",
        "type": "tab",
        "label": "Flow",
        "disabled": false,
        "info": "",
        "env": []
    },
    {
        "id": "38ac22caa29e1daf",
        "type": "change",
        "z": "35e959d48dc8655d",
        "name": "dest / msj",
        "rules": [
            {
                "t": "set",
                "p": "info",
                "pt": "msg",
                "to": "[msg.values]",
                "tot": "jsonata",
                "dc": true
            },
            {
                "t": "set",
                "p": "unit",
                "pt": "msg",
                "to": "1",
                "tot": "num"
            },
            {
                "t": "set",
                "p": "varfc",
                "pt": "msg",
                "to": "16",
                "tot": "num"
            }
        ],
        "action": "",
        "property": "",
        "from": "",
        "to": "",
        "reg": false,
        "x": 380,
        "y": 80,
        "wires": [
            [
                "bde50e161ba0fe7f"
            ]
        ]
    },
    {
        "id": "bde50e161ba0fe7f",
        "type": "function",
        "z": "35e959d48dc8655d",
        "name": "",
        "func": "msg.payload = {};\nlet fc = msg.varfc;\nlet unitid = msg.unit;\nlet address = (~~msg.address);\nlet quantity = (~~msg.quantity);\nlet value = msg.info;\nmsg.payload = { value, fc, unitid, address, quantity};\nreturn msg;",
        "outputs": 1,
        "noerr": 0,
        "initialize": "",
        "finalize": "",
        "libs": [],
        "x": 520,
        "y": 80,
        "wires": [
            [
                "eb99819e101cb7cb"
            ]
        ]
    },
    {
        "id": "eb99819e101cb7cb",
        "type": "modbus-flex-write",
        "z": "35e959d48dc8655d",
        "name": "EscribeWords",
        "showStatusActivities": false,
        "showErrors": true,
        "server": "e0c17133825e418c",
        "emptyMsgOnFail": false,
        "keepMsgProperties": false,
        "x": 680,
        "y": 80,
        "wires": [
            [
                "e6540f68d7783118"
            ],
            [
                "e6540f68d7783118"
            ]
        ]
    },
    {
        "id": "e258bd3fbf593bab",
        "type": "inject",
        "z": "35e959d48dc8655d",
        "name": "",
        "props": [
            {
                "p": "payload"
            },
            {
                "p": "address",
                "v": "90",
                "vt": "num"
            },
            {
                "p": "quantity",
                "v": "3",
                "vt": "num"
            },
            {
                "p": "values",
                "v": "[90000,4000,20000]",
                "vt": "jsonata"
            }
        ],
        "repeat": "",
        "crontab": "",
        "once": false,
        "onceDelay": 0.1,
        "topic": "",
        "payload": "",
        "payloadType": "date",
        "x": 180,
        "y": 80,
        "wires": [
            [
                "38ac22caa29e1daf"
            ]
        ]
    },
    {
        "id": "e6540f68d7783118",
        "type": "debug",
        "z": "35e959d48dc8655d",
        "name": "",
        "active": true,
        "tosidebar": true,
        "console": false,
        "tostatus": true,
        "complete": "payload",
        "targetType": "msg",
        "statusVal": "payload",
        "statusType": "auto",
        "x": 890,
        "y": 80,
        "wires": []
    },
    {
        "id": "710721c2c539be7e",
        "type": "change",
        "z": "35e959d48dc8655d",
        "name": "dest / msj",
        "rules": [
            {
                "t": "set",
                "p": "info",
                "pt": "msg",
                "to": "$split(msg.values, \",\")",
                "tot": "jsonata",
                "dc": true
            },
            {
                "t": "set",
                "p": "unit",
                "pt": "msg",
                "to": "1",
                "tot": "num"
            },
            {
                "t": "set",
                "p": "varfc",
                "pt": "msg",
                "to": "16",
                "tot": "num"
            }
        ],
        "action": "",
        "property": "",
        "from": "",
        "to": "",
        "reg": false,
        "x": 380,
        "y": 160,
        "wires": [
            [
                "1be7836081fb0345"
            ]
        ]
    },
    {
        "id": "2daae39b1cfacc91",
        "type": "inject",
        "z": "35e959d48dc8655d",
        "name": "",
        "props": [
            {
                "p": "payload"
            },
            {
                "p": "address",
                "v": "90",
                "vt": "num"
            },
            {
                "p": "quantity",
                "v": "3",
                "vt": "num"
            },
            {
                "p": "values",
                "v": "90000,5000,25000",
                "vt": "str"
            }
        ],
        "repeat": "",
        "crontab": "",
        "once": false,
        "onceDelay": 0.1,
        "topic": "",
        "payload": "",
        "payloadType": "date",
        "x": 180,
        "y": 160,
        "wires": [
            [
                "710721c2c539be7e"
            ]
        ]
    },
    {
        "id": "1be7836081fb0345",
        "type": "function",
        "z": "35e959d48dc8655d",
        "name": "",
        "func": "msg.payload = {};\nlet fc = msg.varfc;\nlet unitid = msg.unit;\nlet address = (~~msg.address);\nlet quantity = (~~msg.quantity);\nlet value = msg.info;\nmsg.payload = { value, fc, unitid, address, quantity};\nreturn msg;",
        "outputs": 1,
        "noerr": 0,
        "initialize": "",
        "finalize": "",
        "libs": [],
        "x": 520,
        "y": 160,
        "wires": [
            [
                "8b7c51de746a97af"
            ]
        ]
    },
    {
        "id": "8b7c51de746a97af",
        "type": "modbus-flex-write",
        "z": "35e959d48dc8655d",
        "name": "EscribeWords",
        "showStatusActivities": false,
        "showErrors": true,
        "server": "e0c17133825e418c",
        "emptyMsgOnFail": false,
        "keepMsgProperties": false,
        "x": 680,
        "y": 160,
        "wires": [
            [
                "d717edde2e808b9b"
            ],
            [
                "d717edde2e808b9b"
            ]
        ]
    },
    {
        "id": "d717edde2e808b9b",
        "type": "debug",
        "z": "35e959d48dc8655d",
        "name": "",
        "active": true,
        "tosidebar": true,
        "console": false,
        "tostatus": true,
        "complete": "payload",
        "targetType": "msg",
        "statusVal": "payload",
        "statusType": "auto",
        "x": 890,
        "y": 160,
        "wires": []
    },
    {
        "id": "6b0856502c1ec8f8",
        "type": "change",
        "z": "35e959d48dc8655d",
        "name": "dest / msj",
        "rules": [
            {
                "t": "set",
                "p": "info",
                "pt": "msg",
                "to": "$split(msg.values, \",\")",
                "tot": "jsonata",
                "dc": true
            },
            {
                "t": "set",
                "p": "unit",
                "pt": "msg",
                "to": "1",
                "tot": "num"
            },
            {
                "t": "set",
                "p": "varfc",
                "pt": "msg",
                "to": "16",
                "tot": "num"
            }
        ],
        "action": "",
        "property": "",
        "from": "",
        "to": "",
        "reg": false,
        "x": 380,
        "y": 240,
        "wires": [
            [
                "2f051284ae44d057"
            ]
        ]
    },
    {
        "id": "ff20afe189ebb811",
        "type": "inject",
        "z": "35e959d48dc8655d",
        "name": "",
        "props": [
            {
                "p": "payload"
            },
            {
                "p": "address",
                "v": "90",
                "vt": "num"
            },
            {
                "p": "quantity",
                "v": "3",
                "vt": "num"
            },
            {
                "p": "values",
                "v": "90000,5000,25000",
                "vt": "bin"
            }
        ],
        "repeat": "",
        "crontab": "",
        "once": false,
        "onceDelay": 0.1,
        "topic": "",
        "payload": "",
        "payloadType": "date",
        "x": 180,
        "y": 240,
        "wires": [
            [
                "6b0856502c1ec8f8"
            ]
        ]
    },
    {
        "id": "2f051284ae44d057",
        "type": "function",
        "z": "35e959d48dc8655d",
        "name": "",
        "func": "msg.payload = {};\nlet fc = msg.varfc;\nlet unitid = msg.unit;\nlet address = (~~msg.address);\nlet quantity = (~~msg.quantity);\nlet value = msg.info;\nmsg.payload = { value, fc, unitid, address, quantity};\nreturn msg;",
        "outputs": 1,
        "noerr": 0,
        "initialize": "",
        "finalize": "",
        "libs": [],
        "x": 520,
        "y": 240,
        "wires": [
            [
                "001ea5705b2fd70f"
            ]
        ]
    },
    {
        "id": "001ea5705b2fd70f",
        "type": "modbus-flex-write",
        "z": "35e959d48dc8655d",
        "name": "EscribeWords",
        "showStatusActivities": false,
        "showErrors": true,
        "server": "e0c17133825e418c",
        "emptyMsgOnFail": false,
        "keepMsgProperties": false,
        "x": 680,
        "y": 240,
        "wires": [
            [
                "1a65dca72067e497"
            ],
            [
                "1a65dca72067e497"
            ]
        ]
    },
    {
        "id": "1a65dca72067e497",
        "type": "debug",
        "z": "35e959d48dc8655d",
        "name": "",
        "active": true,
        "tosidebar": true,
        "console": false,
        "tostatus": true,
        "complete": "payload",
        "targetType": "msg",
        "statusVal": "payload",
        "statusType": "auto",
        "x": 890,
        "y": 240,
        "wires": []
    },
    {
        "id": "3119b10ec1b2d13c",
        "type": "change",
        "z": "35e959d48dc8655d",
        "name": "dest / msj",
        "rules": [
            {
                "t": "set",
                "p": "info",
                "pt": "msg",
                "to": "$split(msg.values, \",\")",
                "tot": "jsonata",
                "dc": true
            },
            {
                "t": "set",
                "p": "unit",
                "pt": "msg",
                "to": "1",
                "tot": "num"
            },
            {
                "t": "set",
                "p": "varfc",
                "pt": "msg",
                "to": "16",
                "tot": "num"
            }
        ],
        "action": "",
        "property": "",
        "from": "",
        "to": "",
        "reg": false,
        "x": 380,
        "y": 320,
        "wires": [
            [
                "f2e68a9fb755b1ee"
            ]
        ]
    },
    {
        "id": "11c3fb359dace953",
        "type": "inject",
        "z": "35e959d48dc8655d",
        "name": "",
        "props": [
            {
                "p": "payload"
            },
            {
                "p": "address",
                "v": "90",
                "vt": "num"
            },
            {
                "p": "quantity",
                "v": "3",
                "vt": "num"
            },
            {
                "p": "values",
                "v": "[90000,5000,25000]",
                "vt": "json"
            }
        ],
        "repeat": "",
        "crontab": "",
        "once": false,
        "onceDelay": 0.1,
        "topic": "",
        "payload": "",
        "payloadType": "date",
        "x": 180,
        "y": 320,
        "wires": [
            [
                "3119b10ec1b2d13c"
            ]
        ]
    },
    {
        "id": "f2e68a9fb755b1ee",
        "type": "function",
        "z": "35e959d48dc8655d",
        "name": "",
        "func": "msg.payload = {};\nlet fc = msg.varfc;\nlet unitid = msg.unit;\nlet address = (~~msg.address);\nlet quantity = (~~msg.quantity);\nlet value = msg.info;\nmsg.payload = { value, fc, unitid, address, quantity};\nreturn msg;",
        "outputs": 1,
        "noerr": 0,
        "initialize": "",
        "finalize": "",
        "libs": [],
        "x": 520,
        "y": 320,
        "wires": [
            [
                "afc283d312e9dd5c"
            ]
        ]
    },
    {
        "id": "afc283d312e9dd5c",
        "type": "modbus-flex-write",
        "z": "35e959d48dc8655d",
        "name": "EscribeWords",
        "showStatusActivities": false,
        "showErrors": true,
        "server": "e0c17133825e418c",
        "emptyMsgOnFail": false,
        "keepMsgProperties": false,
        "x": 680,
        "y": 320,
        "wires": [
            [
                "8146271e3314ad9d"
            ],
            [
                "8146271e3314ad9d"
            ]
        ]
    },
    {
        "id": "8146271e3314ad9d",
        "type": "debug",
        "z": "35e959d48dc8655d",
        "name": "",
        "active": true,
        "tosidebar": true,
        "console": false,
        "tostatus": true,
        "complete": "payload",
        "targetType": "msg",
        "statusVal": "payload",
        "statusType": "auto",
        "x": 890,
        "y": 320,
        "wires": []
    },
    {
        "id": "8527a7d8d453d9f0",
        "type": "change",
        "z": "35e959d48dc8655d",
        "name": "dest / msj",
        "rules": [
            {
                "t": "set",
                "p": "info",
                "pt": "msg",
                "to": "$split(msg.values, \",\")",
                "tot": "jsonata",
                "dc": true
            },
            {
                "t": "set",
                "p": "unit",
                "pt": "msg",
                "to": "1",
                "tot": "num"
            },
            {
                "t": "set",
                "p": "varfc",
                "pt": "msg",
                "to": "16",
                "tot": "num"
            }
        ],
        "action": "",
        "property": "",
        "from": "",
        "to": "",
        "reg": false,
        "x": 380,
        "y": 400,
        "wires": [
            [
                "63d94e9bf83ec1ca"
            ]
        ]
    },
    {
        "id": "51f8eca5d3064c79",
        "type": "inject",
        "z": "35e959d48dc8655d",
        "name": "",
        "props": [
            {
                "p": "payload"
            },
            {
                "p": "address",
                "v": "90",
                "vt": "num"
            },
            {
                "p": "quantity",
                "v": "3",
                "vt": "num"
            },
            {
                "p": "values",
                "v": "[90000,5000,25000]",
                "vt": "json"
            }
        ],
        "repeat": "",
        "crontab": "",
        "once": false,
        "onceDelay": 0.1,
        "topic": "",
        "payload": "",
        "payloadType": "date",
        "x": 180,
        "y": 400,
        "wires": [
            [
                "8527a7d8d453d9f0"
            ]
        ]
    },
    {
        "id": "63d94e9bf83ec1ca",
        "type": "function",
        "z": "35e959d48dc8655d",
        "name": "",
        "func": "msg.payload = {};\nlet fc = msg.varfc;\nlet unitid = msg.unit;\nlet address = (~~msg.address);\nlet quantity = (~~msg.quantity);\nlet value = Buffer.from(msg.info, \"utf-8\");;\nmsg.payload = { value, fc, unitid, address, quantity};\nreturn msg;",
        "outputs": 1,
        "noerr": 0,
        "initialize": "",
        "finalize": "",
        "libs": [],
        "x": 520,
        "y": 400,
        "wires": [
            [
                "410a6459144ecfab"
            ]
        ]
    },
    {
        "id": "410a6459144ecfab",
        "type": "modbus-flex-write",
        "z": "35e959d48dc8655d",
        "name": "EscribeWords",
        "showStatusActivities": false,
        "showErrors": true,
        "server": "e0c17133825e418c",
        "emptyMsgOnFail": false,
        "keepMsgProperties": false,
        "x": 680,
        "y": 400,
        "wires": [
            [
                "a4f00a893a7c6498"
            ],
            [
                "a4f00a893a7c6498"
            ]
        ]
    },
    {
        "id": "a4f00a893a7c6498",
        "type": "debug",
        "z": "35e959d48dc8655d",
        "name": "",
        "active": true,
        "tosidebar": true,
        "console": false,
        "tostatus": true,
        "complete": "payload",
        "targetType": "msg",
        "statusVal": "payload",
        "statusType": "auto",
        "x": 890,
        "y": 400,
        "wires": []
    },
    {
        "id": "98622685435f48e2",
        "type": "modbustcp-write",
        "z": "35e959d48dc8655d",
        "name": "Test",
        "topic": "",
        "dataType": "HoldingRegisters",
        "adr": "90",
        "server": "33c1604122b77618",
        "x": 410,
        "y": 680,
        "wires": []
    },
    {
        "id": "88c7c7737ba2c4b7",
        "type": "inject",
        "z": "35e959d48dc8655d",
        "name": "",
        "props": [
            {
                "p": "payload"
            }
        ],
        "repeat": "",
        "crontab": "",
        "once": false,
        "onceDelay": 0.1,
        "topic": "",
        "payload": "[90000,6500,20000]",
        "payloadType": "json",
        "x": 210,
        "y": 680,
        "wires": [
            [
                "98622685435f48e2"
            ]
        ]
    },
    {
        "id": "c6956cc1826a3baf",
        "type": "modbustcp-write",
        "z": "35e959d48dc8655d",
        "name": "Test",
        "topic": "",
        "dataType": "HoldingRegisters",
        "adr": "90",
        "server": "33c1604122b77618",
        "x": 410,
        "y": 740,
        "wires": []
    },
    {
        "id": "79a71cc411136bab",
        "type": "inject",
        "z": "35e959d48dc8655d",
        "name": "",
        "props": [
            {
                "p": "payload"
            }
        ],
        "repeat": "",
        "crontab": "",
        "once": false,
        "onceDelay": 0.1,
        "topic": "",
        "payload": "90000,6500,20000",
        "payloadType": "str",
        "x": 210,
        "y": 740,
        "wires": [
            [
                "c6956cc1826a3baf"
            ]
        ]
    },
    {
        "id": "5a26073984e9d02a",
        "type": "modbustcp-write",
        "z": "35e959d48dc8655d",
        "name": "Test",
        "topic": "",
        "dataType": "HoldingRegisters",
        "adr": "90",
        "server": "33c1604122b77618",
        "x": 410,
        "y": 800,
        "wires": []
    },
    {
        "id": "b094c64b4f2316aa",
        "type": "inject",
        "z": "35e959d48dc8655d",
        "name": "",
        "props": [
            {
                "p": "payload"
            }
        ],
        "repeat": "",
        "crontab": "",
        "once": false,
        "onceDelay": 0.1,
        "topic": "",
        "payload": "[90000,6500,20000]",
        "payloadType": "bin",
        "x": 170,
        "y": 800,
        "wires": [
            [
                "5a26073984e9d02a"
            ]
        ]
    },
    {
        "id": "5ee5e4278839e319",
        "type": "modbustcp-write",
        "z": "35e959d48dc8655d",
        "name": "Test",
        "topic": "",
        "dataType": "HoldingRegisters",
        "adr": "90",
        "server": "33c1604122b77618",
        "x": 410,
        "y": 860,
        "wires": []
    },
    {
        "id": "d37c9683a550a89a",
        "type": "inject",
        "z": "35e959d48dc8655d",
        "name": "",
        "props": [
            {
                "p": "payload"
            }
        ],
        "repeat": "",
        "crontab": "",
        "once": false,
        "onceDelay": 0.1,
        "topic": "",
        "payload": "[90000,6500,20000]",
        "payloadType": "jsonata",
        "x": 170,
        "y": 860,
        "wires": [
            [
                "5ee5e4278839e319"
            ]
        ]
    },
    {
        "id": "e0c17133825e418c",
        "type": "modbus-client",
        "name": "MODBUS",
        "clienttype": "tcp",
        "bufferCommands": false,
        "stateLogEnabled": false,
        "queueLogEnabled": false,
        "tcpHost": "192.168.143.250",
        "tcpPort": "502",
        "tcpType": "DEFAULT",
        "serialPort": "/dev/ttyUSB",
        "serialType": "RTU-BUFFERD",
        "serialBaudrate": "9600",
        "serialDatabits": "8",
        "serialStopbits": "1",
        "serialParity": "none",
        "serialConnectionDelay": "100",
        "serialAsciiResponseStartDelimiter": "0x3A",
        "unit_id": "1",
        "commandDelay": "50",
        "clientTimeout": "100",
        "reconnectOnTimeout": true,
        "reconnectTimeout": "2000",
        "parallelUnitIdsAllowed": false
    },
    {
        "id": "33c1604122b77618",
        "type": "modbustcp-server",
        "name": "Modbus",
        "host": "192.168.143.250",
        "port": "502",
        "unit_id": "1",
        "reconnecttimeout": ""
    }
] ```
2

I keep trying, no success :frowning:

I would really appreciate help from experts like you!

This is the Node default:

RangeError: The value of "value" is out of range. It must be >= 0 and <= 65535. Received 90000

3

Hello,

Do you need more information to help me?

4

Try this with an input

[
    {
        "id": "6440d0ce.db23c",
        "type": "modbus-write",
        "z": "2bd6dc17.504c44",
        "name": "40793",
        "showStatusActivities": false,
        "showErrors": true,
        "unitid": "3",
        "dataType": "MHoldingRegisters",
        "adr": "40793",
        "quantity": "2",
        "server": "b6c6500c.41cc1",
        "emptyMsgOnFail": false,
        "keepMsgProperties": false,
        "x": 850,
        "y": 540,
        "wires": [
            [],
            []
        ]
    },
    {
        "id": "7c320828.55b95",
        "type": "buffer-parser",
        "z": "2bd6dc17.504c44",
        "name": "",
        "data": "payload",
        "dataType": "msg",
        "specification": "spec",
        "specificationType": "ui",
        "items": [
            {
                "type": "uint16be",
                "name": "data",
                "offset": 0,
                "length": 2,
                "offsetbit": 0,
                "scale": "1",
                "mask": ""
            }
        ],
        "swap1": "",
        "swap2": "",
        "swap3": "",
        "swap1Type": "swap",
        "swap2Type": "swap",
        "swap3Type": "swap",
        "msgProperty": "payload",
        "msgPropertyType": "str",
        "resultType": "value",
        "resultTypeType": "output",
        "multipleResult": true,
        "fanOutMultipleResult": false,
        "setTopic": true,
        "outputs": 1,
        "x": 670,
        "y": 540,
        "wires": [
            [
                "6440d0ce.db23c",
                "6cbc3abe.37cd9c"
            ]
        ]
    },
    {
        "id": "7edbef66.8f5278",
        "type": "buffer-maker",
        "z": "2bd6dc17.504c44",
        "name": "",
        "specification": "spec",
        "specificationType": "ui",
        "items": [
            {
                "name": "item1",
                "type": "uint32be",
                "length": 1,
                "dataType": "msg",
                "data": "payload"
            }
        ],
        "swap1": "",
        "swap2": "",
        "swap3": "",
        "swap1Type": "swap",
        "swap2Type": "swap",
        "swap3Type": "swap",
        "msgProperty": "payload",
        "msgPropertyType": "str",
        "x": 390,
        "y": 540,
        "wires": [
            [
                "7c320828.55b95"
            ]
        ]
    },
    {
        "id": "b6c6500c.41cc1",
        "type": "modbus-client",
        "name": "SBS2.5",
        "clienttype": "tcp",
        "bufferCommands": true,
        "stateLogEnabled": false,
        "queueLogEnabled": false,
        "tcpHost": "192.168.168.55",
        "tcpPort": "502",
        "tcpType": "TCP-RTU-BUFFERED",
        "serialPort": "/dev/ttyUSB",
        "serialType": "RTU-BUFFERD",
        "serialBaudrate": "9600",
        "serialDatabits": "8",
        "serialStopbits": "1",
        "serialParity": "none",
        "serialConnectionDelay": "100",
        "serialAsciiResponseStartDelimiter": "",
        "unit_id": "3",
        "commandDelay": "10",
        "clientTimeout": "1000",
        "reconnectOnTimeout": true,
        "reconnectTimeout": "2000",
        "parallelUnitIdsAllowed": false
    }
]

you need node-red-contrib-buffer-parser & node-red-contrib-modbus

1 Like
5

Thank you @Becker

Trying...

6

¡No success! :confused:

Your example works fine and separates the two 16bit chunks and encodes them fine :wink:

But it doesn't work for me on my Modbus device, but thanks to your answer, I have detected why it doesn't work...
The device that only receives the 1st 16bits...so even though the register is 32bits, I cannot send the 32bits direct register.
I'm going to fix it with programming on the Modbus device directly.

Thank you for your nice help :wink: :+1:t2:

7

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