Modbus result = 32752

General
1

Hi,

I have a kohler apm 402 generator controller and i successfully connected to it with the node-red-contrib-modbus

What is stange is that i get correct readings when i shift all registers from 1. Like i get the fuel level on register 1105 when it is supposed to be on register 1106.

Also a lot of the responses i have are 32752 or 32767 wich is, i think, the max value of an int16. Others wich are Strings give 0.

I tried to decode with the buffer parser with every settings, byte swap and whatnot and can't get a logical value out of them.
Below is the register chart.
Any ideas?

tableau modbus
tableau modbus808×820 103 KB

2

There is often an off by one error in docs. This is due to some manufacturers starting from 1 and others starting from zero. Then there are typos!

Not really, you have not supplied a capture of sample input data nor any realistic example of what the final value(s) should be.

Pick a register, provide real captured data in a function node or template and your progress on buffer parser flow and export it. Also, provide the value you expect it to be.

3

the thing is that it's the same value from a bunch of registers, ex: from 1106 to 1116, 1119 to 1127 alaways the same array withe that number in it: [32752], those registers can't have the same value.

I don't understand how "to put captured data in a function node"

4

Add a debug to the end of the modbus node.
Set the debug to output the COMPLETE MESSAGE
Use the Copy Value button
Paste the copied code into a function like this:

return <paste-copy-data>

Getting data from messages

There’s a great page in the docs (Working with messages : Node-RED) that will explain how to use the debug panel to find the right path/value for any data item.

Pay particular attention to the part about the buttons that appear under your mouse pointer when you over hover a debug message property in the sidebar.

BX00Cy7yHi

5

Thank you Steve, i was not aware how to do that

return <paste-copy-data>

But like i said a bunch of registers give me the same value.

[
    {
        "id": "5b592e561f6a0087",
        "type": "buffer-parser",
        "z": "210d4bb2856c7935",
        "name": "",
        "data": "payload",
        "dataType": "msg",
        "specification": "spec",
        "specificationType": "ui",
        "items": [
            {
                "type": "int16be",
                "name": "item1",
                "offset": 0,
                "length": 1,
                "offsetbit": 0,
                "scale": "1",
                "mask": ""
            }
        ],
        "swap1": "",
        "swap2": "",
        "swap3": "",
        "swap1Type": "swap",
        "swap2Type": "swap",
        "swap3Type": "swap",
        "msgProperty": "payload",
        "msgPropertyType": "str",
        "resultType": "value",
        "resultTypeType": "return",
        "multipleResult": false,
        "fanOutMultipleResult": false,
        "setTopic": true,
        "outputs": 1,
        "x": 490,
        "y": 1380,
        "wires": [
            [
                "50008624a981021c"
            ]
        ]
    },
    {
        "id": "3e08f6b03c95841b",
        "type": "function",
        "z": "210d4bb2856c7935",
        "name": "function 2",
        "func": "\nreturn { \"topic\": \"ddd203704ceff98f\", \"messageId\": \"67a130531e302eb43e8bb489\", \"payload\": [32752], \"queueLengthByUnitId\": { \"unitId\": 1, \"queueLength\": 0 }, \"queueUnitId\": 1, \"unitId\": 1, \"modbusRequest\": { \"value\": 1738616915219, \"unitid\": \"1\", \"fc\": 3, \"address\": \"1109\", \"quantity\": \"1\", \"messageId\": \"67a130531e302eb43e8bb489\" }, \"responseBuffer\": { \"data\": [32752], \"buffer\": [127, 240] }, \"_msgid\": \"82c3756a384214f2\" }",
        "outputs": 1,
        "timeout": 0,
        "noerr": 0,
        "initialize": "",
        "finalize": "",
        "libs": [],
        "x": 320,
        "y": 1420,
        "wires": [
            [
                "5b592e561f6a0087",
                "89ee906547774cec",
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    },
    {
        "id": "2cef89322d0395b9",
        "type": "inject",
        "z": "210d4bb2856c7935",
        "name": "",
        "props": [
            {
                "p": "payload"
            },
            {
                "p": "topic",
                "vt": "str"
            }
        ],
        "repeat": "",
        "crontab": "",
        "once": false,
        "onceDelay": 0.1,
        "topic": "",
        "payload": "",
        "payloadType": "date",
        "x": 150,
        "y": 1420,
        "wires": [
            [
                "3e08f6b03c95841b"
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    },
    {
        "id": "50008624a981021c",
        "type": "debug",
        "z": "210d4bb2856c7935",
        "name": "debug 49",
        "active": true,
        "tosidebar": true,
        "console": false,
        "tostatus": false,
        "complete": "false",
        "statusVal": "",
        "statusType": "auto",
        "x": 660,
        "y": 1380,
        "wires": []
    },
    {
        "id": "89ee906547774cec",
        "type": "buffer-parser",
        "z": "210d4bb2856c7935",
        "name": "",
        "data": "payload",
        "dataType": "msg",
        "specification": "spec",
        "specificationType": "ui",
        "items": [
            {
                "type": "int16be",
                "name": "item1",
                "offset": 0,
                "length": 1,
                "offsetbit": 0,
                "scale": "1",
                "mask": ""
            }
        ],
        "swap1": "",
        "swap2": "",
        "swap3": "",
        "swap1Type": "swap",
        "swap2Type": "swap",
        "swap3Type": "swap",
        "msgProperty": "payload",
        "msgPropertyType": "str",
        "resultType": "value",
        "resultTypeType": "return",
        "multipleResult": false,
        "fanOutMultipleResult": false,
        "setTopic": true,
        "outputs": 1,
        "x": 490,
        "y": 1420,
        "wires": [
            [
                "c4782b6323c9f752"
            ]
        ]
    },
    {
        "id": "c4782b6323c9f752",
        "type": "debug",
        "z": "210d4bb2856c7935",
        "name": "debug 51",
        "active": true,
        "tosidebar": true,
        "console": false,
        "tostatus": false,
        "complete": "false",
        "statusVal": "",
        "statusType": "auto",
        "x": 660,
        "y": 1420,
        "wires": []
    },
    {
        "id": "b43e7fc1cf70f330",
        "type": "buffer-parser",
        "z": "210d4bb2856c7935",
        "name": "",
        "data": "payload",
        "dataType": "msg",
        "specification": "spec",
        "specificationType": "ui",
        "items": [
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                "name": "item1",
                "offset": 0,
                "length": 1,
                "offsetbit": 0,
                "scale": "1",
                "mask": ""
            }
        ],
        "swap1": "swap16",
        "swap2": "",
        "swap3": "",
        "swap1Type": "swap",
        "swap2Type": "swap",
        "swap3Type": "swap",
        "msgProperty": "payload",
        "msgPropertyType": "str",
        "resultType": "value",
        "resultTypeType": "return",
        "multipleResult": false,
        "fanOutMultipleResult": false,
        "setTopic": true,
        "outputs": 1,
        "x": 490,
        "y": 1460,
        "wires": [
            []
        ]
    },
    {
        "id": "7851ffe3ec7f3edf",
        "type": "buffer-parser",
        "z": "210d4bb2856c7935",
        "name": "",
        "data": "payload",
        "dataType": "msg",
        "specification": "spec",
        "specificationType": "ui",
        "items": [
            {
                "type": "int16le",
                "name": "item1",
                "offset": 0,
                "length": 1,
                "offsetbit": 0,
                "scale": "1",
                "mask": ""
            }
        ],
        "swap1": "",
        "swap2": "",
        "swap3": "",
        "swap1Type": "swap",
        "swap2Type": "swap",
        "swap3Type": "swap",
        "msgProperty": "payload",
        "msgPropertyType": "str",
        "resultType": "value",
        "resultTypeType": "return",
        "multipleResult": false,
        "fanOutMultipleResult": false,
        "setTopic": true,
        "outputs": 1,
        "x": 490,
        "y": 1460,
        "wires": [
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    {
        "id": "40a8ab858fefba6e",
        "type": "debug",
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        "active": true,
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        "console": false,
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        "complete": "false",
        "statusVal": "",
        "statusType": "auto",
        "x": 660,
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        "wires": []
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]
6

You have only requested 1 register (1109) - therefore you can only parse one value. That is highly wasteful (leads to increased traffic, inconsistent data, inextensible/unmaintainable flows)

If you request as many as possible (up to 125) you can parse them all at once.

Anyhow, as requested , you have not provided the expected value for this register. Are you expecting it to be parsed to a negative number? Somewhere between 0~99? Something over 20000? A clue would make this easier. In fact, providing a larger chunk of data would help determine if the addresses are out of step (easier to see a pattern)