Lower Case (LOWER)
The LOWER instruction converts the alphabetical characters in a string to lower case characters.
Available Languages
Ladder Diagram
_v1.png/_jcr_content/renditions/original)
FactoryTalk Design Studio
DSL - Ladder DiagramLOWER(Source,Dest);
Operands
Ladder Diagram
Operand | Type | Format | Description |
|---|---|---|---|
Source | String | Tag | The tag that contains the characters you want to convert to lower case |
Destination | String | Tag | The tag to store the characters in lower case |
The LOWER instruction converts all the letters in the Source to lower case, and places the result in the Destination.
- ASCII characters are case-sensitive. Upper case A ($41) is not equal to lower case a ($61).
- If operators directly enter ASCII characters, convert the characters to all upper case or lower case before you compare them.
Any characters in the Source string that are not letters remain unchanged.
Affects Math Status Flags
No
Major/Minor Faults
Type | Code | Cause | Recovery Method |
|---|---|---|---|
4 | 51 | The LEN value of the string tag is greater than the DATA size of the string tag. | Check that no instruction is writing to the LEN member of the string type tag. In the LEN value, enter the number of characters that the string contains. |
4 | 52 | The output string is larger than the destination | Create a new string type that is large enough for the output string. Use the new string type as the data type for the destination. |
Execution
Ladder Diagram
Condition/State | Action Taken |
|---|---|
Prescan | N/A |
Rung-condition-in is false | N/A |
Rung-condition-in is true | The instruction executes. |
Postscan | N/A |
Examples
To find information about a specific item, an operator enters the item number into an ASCII terminal. After the controller reads the input from a terminal (terminal_read is set), the LOWER instruction converts the characters in item_number to all upper case characters and stores the result in item_number_lower_case. A subsequent rung then searches an array for characters that match those in item_number_lower_case.
Ladder Diagram
Provide Feedback