Schneider modbus Float32 IEM3350

[tcaccia]

Hi all,

I'm trying to convert the array that the modbus receiver keep from the IEM3350
I have some problem:
when I put this function that I've found on a YouTube video from an official schneider tutorial, it doesn't work:

const buf = Buffer.from(msg.responseBuffer.buffer);
const value = buf.readFloatBE();
msg.payload = value;

return msg;

Then, I tried with another function that I founded on the web; sometimes works...:

let pay = msg.payload;

const buf = Buffer.allocUnsafe(4);
buf.writeUInt16BE(pay[0],2);
buf.writeUInt16BE(pay[1],0);

msg.payload = buf.readFloatBE(0);
return msg;

...but sometimes give me this error:

"RangeError [ERR_OUT_OF_RANGE]: The value of "value" is out of range. It must be >= -32768 and <= 32767. Received 45267"

Have you the same problem?
Someone solved it?

Thanks!

[Steve-Mcl]

@tcaccia

Have you the same problem

Many have.

Do your self a favour and use node-red-contrib-buffer-parser it takes care of all the details.

There are quite a few threads that do this - take a look in particular this one and this one and this one

[tcaccia]

Thanks for your support,
This module seems very interesting.
Anyway, I've found this function on the web and it's working good...

var ui16 = new Uint16Array(msg.payload);
var fl32 = new Float32Array(ui16.buffer, ui16.byteOffset, ui16.byteLength / Float32Array.BYTES_PER_ELEMENT);
msg.payload= fl32;
return msg;