Allen-Bradley Logix5000 - Relay Ladder; Structured Text

Rockwell Automation Publication 1756-RM003N-EN-P - October 2011 613
ASCII String Instructions (CONCAT, DELETE, FIND, INSERT, MID) Chapter 18
Execution:
Example: ASCII information from a terminal contains a header character. After the controller reads
the data (term_read.EM is set) the DELETE instruction removes the header character.
Relay Ladder
Structured Text
IF term_read.EM THEN
DELETE(term_input,1,1,term_text);
term_read.EM := 0;
END_IF;
Condition Relay Ladder Action Structured Text Action
Prescan The rung-condition-out is set to false. No action taken
Rung-condition-in is false The rung-condition-out is set to false. N/A
Rung-condition-in is true The instruction executes.
The rung-condition-out is set to true.
N/A
EnableIn is set N/A EnableIn is always set.
The instruction executes.
Instruction execution The instruction deletes the specified characters.
Postscan The rung-condition-out is set to false. No action taken.
term_read.EM
String Delete
Source term_input
'$0655'
Qty 1
Start 1
Dest term_text
'55'
DELETE