Splitting hex value

[atomic10]

Building an interface with a touchscreen from 4D Systems - in the documentation it states to write to a number on the screen, the value needs to be:
Value(msb:lsb)

This is the 2 byte value, Value(msb):Value(lsb), that is used in the
message transmissions to and from the host. For example, if the LED
Digits value is 5645 (0x160D) the 2 byte value will be:
Value(msb) = 0x16
Value(lsb) = 0x0D

I am receiving a value from Modbus that I want to pass onto the screen,
ie. 1350 rpm or 0x546 but cannot get my head around how to split the value into two bytes.

Appreciate any advice.

[atomic10]

Apologies for answering my own question, but after some tinkering I come up with this -

var b1 = 0;
var b2 = 0;
var num = msg.payload;

b1 = (num >> 8);
b2 =  (num & 0xFF);
msg = {payload: ([b1,b2,num])};
return msg;

and it works fine. Feel free to critique or add further advice.

[dceejay]

Perfectly fine and readable.

[atomic10]

Much appreciated dceejay.
Got stuck in my head with trying to spit a hex value rather than the actual value.
Hex, Dec, Bin - it doesn't care just use the tools you have

[JayDickson]

Apologies for answering my own question

That's not something to apologize for. To the contrary, now someone else might stumble across this in a google search and benefit from it.

[mike1976]

Hello,

1. sorry for my bad english

I´m a node red noob.
I have a sensor it brings me by i2c - 8 bytes reotur.
So thats my problem, how i can get only 2 bytes in decimal?
I need byte:0 and byte:4

Pleas can someone help me, pleas.

[mike1976]

nobody has an idea

[cymplecy]

We were all asleep in my country
This change node will get you the 4th item - 0 would get you the 1st