[Modbus Flex Getter] Queue is reset on timeout

[AdrienAdB]

Which node-red-contrib-modbus version are you using?

5.25

What happened?

• Enable queuing
• Send messages by polling multiple unitIds (from 1 to 4)

const registers = [
    {
        'fc': 4,
        'unitid': 1,
        'address': 0xD010,
        'quantity': 2,
    },
    {
        'fc': 4,
        'unitid': 2,
        'address': 0xD010,
        'quantity': 2,
    },
    {
        'fc': 4,
        'unitid': 3,
        'address': 0xD010,
        'quantity': 2,
    },
    {
        'fc': 4,
        'unitid': 4,
        'address': 0xD010,
        'quantity': 2,
    }
]

for (let index = 0; index < registers.length; index++) {
    msg.payload = registers[index];
    node.send(msg);    
}

• In normal conditions, devices will reply and data can be processed. OK.
• But if unitId 2 fails on timeout, client reconnects, but queue messages are being reset. Devices 3,4 won't be called.

I found way to quick fix by adding rate limiter before the modbus getter, however polling becomes too slow, expecially when you have 30+ devices on the bus.

Anyway to prevent queue reset on reconnect?

Server

Modbus-Server Node

How can this be reproduced?

Described above.

What did you expect to happen?

Queue to no reset on timeout error

Other Information

No response

[biancode]

It gets a reset from the problem complexity of what is actual happened. You can handle it via your own queue in Node-RED in that case.

[github-actions]

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