read 2 spaces with node-red-contrib-modbustcp

General
1

Hi, I use your "node-red-contrib-modbustcp".

I want to read 2 spaces of my modbustcp pv converter

I want to get the register 5002 to 5036 and it works well.

But I can not read the registers 12999 to 13077 at the same time :frowning:

If I try to read 5002 to 13077 it look like the Array is to big. So I think i have to read it in 2 blocks.

In the doc I read I can use:

[
{
"name": "Reg1",
"address": 4999,
"quantity": 72,
"dataType": "FC4",
"intervall": 15000,
"ieeeBE": true,
"ieeeType": "off"
},
{
"name": "Reg2",
"address": 12999,
"quantity": 78,
"dataType": "FC4",
"intervall": 15000,
"ieeeBE": true,
"ieeeType": "off"
}
]

but it doesn't work.

Please can you help me?

2

It is not possible to read more than 125 items in a modbus request due to the specification design. You will have to read these in two separate goes. I would recommend you do not poll at the same time but sequence them one after another.

3

Thanks for answer.

but how I have to do this?

4

wire things in series

e.g: Modbus Serial - Whole bus disconnects when one device drops - #16 by Steve-Mcl

5

Hi,

I use this ModBus Node https://flows.nodered.org/node/node-red-contrib-modbustcp

If I use there a 2. instance of the node the communication get fail.

The documentation say, I have to use a "multiple input"

[
    {
        "name": "Reg1",
        "address": 4999,
        "quantity": 72,
        "dataType": "FC4",
        "intervall": 15000,
        "ieeeBE": true,
        "ieeeType": "off"
    },
    {
        "name": "Reg2",
        "address": 12999,
        "quantity": 78,
        "dataType": "FC4",
        "intervall": 15000,
        "ieeeBE": true,
        "ieeeType": "off"
    }
]

But if I connect a inject node to the Modbus node I get a thousand messages per second.
I am a newbie in node red.
Can someone please explain to me how I pass the "multiple input" correctly to the Modbus node?

It looks like I am not allowed to upload attachments yet. That's why I save my flow here:

my ModBus flow

Thanks a lot

6

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