Split up / merge 2bytes to num or hex

Paba

Hello everyone,

i'm receiving 2 bytes from a plc and wonder if there's a way to merge them. I thought about 'convert' them to hexadecimal or just add the binary data together..

for example .. incoming values byte 1: 76, byte 2: 162  -- desired result: num: 19618

        0x4C & 0xA2  --> 0x4CA2

or    01001100 & 10100010  --> 0100110010100010

 and then convert it to decimal..

lemster68

Is this via a group input?  If so, why not make one, sixteen bit group?

Paba

yes, but for tests i'm working with a virtual irc5 and think i only can use<br>

https://robotapps.robotstudio.com/#/viewApp/2cab7b4f-754c-415b-a32c-cbe4da9353e9

(RSConnectGIOToSnap7)

which only provides singles bytes..

For real profinet connection lateron, i already set up 16bit groups.. but for now this wont work i think.

Correct me if i'm wrong

Paba

Ok i've found the correct syntax (ByteToStr(byte\Hex)).. was'nt as hard as i expected

    FUNC num mergedX(byte x0,byte x1)
        VAR bool b_temp;
        Xkoord:=hexToDec(ByteToStr(x0\Hex)+ByteToStr(x1\Hex));
        b_temp:=StrToVal(Xkoord,mergedbytes);
        RETURN mergedbytes;
    ENDFUNC

Improvements?

DenisFR

Hello,

You can define a group encompass your bytes.

Like:

<div>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; -Name "giFirstByte" -SignalType "GI" -Device "MyPNDevice" -DeviceMap "0-7"<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; -Name "giSecondetByte" -SignalType "GI" -Device "MyPNDevice" -DeviceMap "8-15"<br></div>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; -Name "giMyWord" -SignalType "GI" -Device "MyPNDevice" -DeviceMap "0-15"

Micky

Hello,

you can calculate the value as follows:

TPWrite "Value: "\num:=CalcValue(76,162);

FUNC num CalcValue(byte byte1,byte byte2)
    RETURN byte1*256+byte2;
ENDFUNC

BR
Micky

Paba

Ok this looks better.. but when i do so, the result is byte-swapped..

i tried to map the word vice versa but then it comes to a nonsense result.

Bytes swapped:

... dont know:

Paba

Thanks Micky, this works as expected.

Denis, can you tell me what i've mapped wrong?

Best Greetings.

lemster68

What if you map first byte to second and vice versa?  Leave word as is.  Or inverse map first and second byte, also leave word as is.

Paba

yes that's propably the simplest way.. too easy to think about it   2nd idea wont work but mapping first to second byte is doing the job.

Thank you all

Micky

Hello Papa,

why don't you combine the two bytes to a group input (16 bit), then you save yourself the later conversion

You can define the signal mapping for the group inputs as follows:
"16-23,24-31"
You can also use here the bit or byte swap, e.g. "23-16,31-24"

best regards
Micky

Paba

Thx Mickey, thats the way i'm doing it right now.

First Byte mapped from 24-31, second Byte from 16-23 (to avoid byte swapping), Word mapped 16-31 and everything works fine