Concatenate 2 hex buffer and convert

[bolfox]

Hi to all,

i need to concatenate 2 buffer (first 2, knx.rawValue[0] and knx.rawValue[a]) in hex like 0x08 + 0xcd, take 08+cd -> 08cd and convert to decimal

08cd = 2253 then add a , after the first 3 digit to receive a 225,3 Volt

If necessary i have alredy the two buffer knx.rawValue[0] and knx.rawValue[1] separated.

Tnx for the help

[Colin]

You only have one Buffer, it is in msg.knx.rawValue and it is 12 bytes long.
Have a look at node-red-contrib-buffer-parser, it is designed for exactly these problems.

[bolfox]

@Colin

msg.knx.rawValue

Tnx, i'm alredy trying it, but how to select the buffer string 1+2 or 5+6?

[Steve-Mcl]

@bolfox

but how to select the buffer string 1+2 or 5+6

[bolfox]

Tnx Steve for all your clarification, now i can try to decode all the message.

If i put the /10 as your example it works one time and one not, if i leave 1 it works always.

[Steve-Mcl]

Can you set debug node to show complete message. Also and another debug set to show complete message before the buffer parser node. Have a look at the data in the msg when it fails. Is there anything different or odd?

[bolfox]

After the parser WORKING

Before the parser

After the parser NOT WORKING

Before the parser when NOT WORKING

[bolfox]

Ok, find the problem

With scale /10 it works 1 time 1 time no, with scale 0.1 it works always