Hi,

what ist last number Hex 03 for a sign? It´s a special sign, so the $ will be inserted. A character string can also contain special characters. The escape character $ is used to identify control characters, dollar signs and single quotation marks. 

STRING

Regards,

Towome

To add some triviality..
The last ASCII character you have there is a non-printable character. 

Figure 1. ETX = End of text

See also End-of-Text character.

It is possible to filter that character out, when using serial communications. The configuration allows to define the front and end characters in a message string.

The last character is HEX 16#03.  In the string, that gets represented as $03.  16#03 is not a printable string character, which is why Siemens (in the string documentation) shows it as $03 (instead of 16#03 or 0x03 as other hex representation examples).

Since you know in advance this ETX character is going to be there, you can subtract 1 from the # of bytes received when converting the array of char in the input buffer into a Siemens String.

Then the $03 will not exist in the converted string.

Look at the device protocol where it says it adds the ETX char at the end of the transmitted data - to let you know that's the end of the data for that data package.