ReadHoldingRegisters offset

[lfernando-silva]

Well, here I am again, thanks for your atention.

So, I need to read from de 40001 to 40344 holding register, and I have understood that , to do this, I need to call readHoldingRegisters three times.

But the interval doesn't make sense for me. After some time testing the reads, I could read it make the follow call:

//after client configurations
client.on('connect', function () {

var reads = [
        client.readHoldingRegisters(0, 127), //40001 to 40127
        client.readHoldingRegisters(127, 255), //40128 to 40254
        client.readHoldingRegisters(254, 346) //40255 to 40344
    ];

Promise
        .all(reads)
        .then(function (data) {
            console.log(data);
        }).error(function (err) {
            console.log(err);
        }).finally(function () {
            client.close();
        });
});

I tried to use Simply Modbus TCP Client 7.1.2 to simulate the calls, but it doesn't work well, so I don't know if it's a modbus protocol problem, just a bug in the module or just I didn't understand the protocol... what can it be?

[lfernando-silva]

My mistake again. The second param is, actually, the bytes quantity and not the last modbus adress in the offset.

So the right read is something like

    var reads = [
        client.readHoldingRegisters(0, 127), //40001 to 40127
        client.readHoldingRegisters(127, 127), //40128 to 40254
        client.readHoldingRegisters(254, 89) //40255 to 40344
    ];

sorry about this, again!