632 Rockwell Automation Publication 1756-RM003N-EN-P - October 2011
Chapter 19 ASCII Conversion Instructions (STOD, STOR, DTOS, RTOS, UPPER, LOWER)
Example: To find information about a specific item, an operator enters the catalog number
of the item into an ASCII terminal. After the controller reads the input from a
terminal (terminal_read.EM is set), the UPPER instruction converts the
characters in catalog_number to all upper case characters and stores the result in
catalog_number_upper_case. A subsequent rung then searches an array for
characters that match those in catalog_number_upper_case.
Relay Ladder
Structured Text
IF terminal_read.EM THEN
UPPER(catalog_number,catalog_number_upper_case);
terminal_read.EM := 0;
END_IF;