Function extension:
UTF8 is a more widely used byte-oriented encoding format for Unicode characters.
The first 128 characters from 0 to 127 are compatible with ASCII encoding.
The characters are encoded in different lengths from 1 to 4 bytes.
The PLC Designer V4 supports UTF8 encoding for the STRING data type. In the 'Settings' dialog (menu 'Project' > 'Project settings', category 'Compile options') there is the checkbox 'UTF8 encoding for STRING'. If this checkbox is ticked,
- all STRING strings are encoded with UTF8
- all STRING variables are decoded with UTF8 during monitoring
- convert STRING conversion functions from and to UTF8.
Independent of this compile option, pragma directives are now available for monitoring UTF8 strings:
- for STRING: {attribute 'monitoring_encoding' := 'UTF-8'}
- for Unicode characters of data type UDINT: {attribute 'monitoring_encoding' := 'UnicodeCharacter'}
UTF8 characters can be entered as an escape sequence, e.g. $u00002126 = Ω.
Offline:
Online:
The diagnosis has been extended for the use of UTF8 strings:
- New warning:
C0555: The string literal '....' contains non-representable characters. ...' - Static Analysis Light:
In the 'Static Analysis Light' category of the project settings, the additional compilation check 'Suspicious operation on string' can be activated, for checking e.g. of: - index access str[2]
- ADR(str)
- Calls to STANDARD string functions with index accesses (all except CONCAT and LEN)
Included in the following products:
[Automatic Translation]
