ProSoft Technology ProSoft i-View - Manual (Page 45)

ProSoft i-View ♦ Mobile Process Monitoring and Control Application Data Source Files
Version 2.0.2 User Manual
ProSoft Technology, Inc. Page 45 of 106
September 29, 2011
3.1.14 Use of International Characters in PLC Strings
You can store international Strings in PLCs with ProSoft i-View just as easily as
you do with ASCII strings. ProSoft i-View will use the source file encoding
identification to decode/encode strings onto raw bytes in the PLC.
When storing international Strings into PLCs you must expect the number of
bytes used, and thus the PLC string length, to be larger than the number of
characters the string actually holds. This is particularly notorious when storing
Chinese or Japanese strings in PLCs.
The UTF-8 encoding, for instance, can use up to 6 bytes per character in a PLC.
However, this does not affect how strings are allocated in ProSoft i-View or the
behavior of String methods and operators in expressions, since these always
refer to actual characters and actual character lengths regardless of encoding.
Of couse, if you only use English or ASCII characters with an encoding that is
backward compatible with ASCII, or you use the Latin1 encoding, only one byte
per character will be allocated in your PLC to store strings.