The string_Util_Intern is not the library I referred to. With a CONCAT function (also with the string util library) a search is done for the NULL character. If you concatenate 20000 characters to one string, then the longer the string, the longer it takes to find this NULL character.
Create a (global) array of Messages: aMessage : ARRAY[0..NR_OF_MESSAGES-1] OF CAN.RxMESSAGE; Then add each received message to the array. IF UserVarGlobal.g_countMsg_RPMset < NR_OF_MESSAGES THEN aMessage[UserVarGlobal.g_countMsg_RPMset] := Message; UserVarGlobal.g_countMsg_RPMset := UserVarGlobal.g_countMsg_RPMset + 1; END_IF
See: https://forge.codesys.com/prj/codesys-example/element-collect/home/Home/ This contains an application "OnlineChangeSafeLinkedListExample". What you should do is create a new interface which has your "Priority" property. Then your FB should extend the base element function block and implement your own interface: E.g. FUNCTION_BLOCK MyElement EXTENDS COL.LinkedListElementBase IMPLEMENTS I_MyInterface Then the __QUERYINTERFACE does the magic to check if your "element" also implements your interface....
The new (UTF8) string library is faster and can handle large strings. https://content.helpme-codesys.com/en/CODESYS%20String%20Libraries/_strlib_start_page.html PS, in CODESYS, the maximum string length is not 255 characters. The String functions of the standard library are limited to strings of 255 characters. But you can use other (memory) functions to handle strings larger than 255 characters.
https://forge.codesys.com/prj/codesys-example/file-utilities/home/Home/
Their is quite a detailed explanation in the help: https://content.helpme-codesys.com/en/CODESYS%20Development%20System/_cds_codesys_modularization.html
See: https://content.helpme-codesys.com/en/CODESYS%20FAQ/_faq_start_page.html
The message means that you (CODESYS) tries to open the function block, but this is not possible because the library which contains the FB is compiled. You either get this when you try to manually open the function block (while editing the application), but it could also happen that an exception occurs in the running application and CODESYS tries to show the location where it occured. If it happened in an FB of the compiled library, it cannot show this and you could get this message too.