String instructions
264
Part II IEC Instructions
LEFT
Copy characters from the left
To add an enable input and enable output to the instruction, select [With EN/ENO] from the
"Instructions" pane (LD, FBD or IL editor). To reuse an instruction select "Recently used" from the
context menu or press <Ctrl>+<Shift>+<v> in the programming window.
PLC types
Availability of LEFT (see page 1328)
If the number of characters to be delivered is greater than the input
string, the complete string will be copied to the output variable
(output_string).
If the output string is longer than the length defined for the output
variable in the field "Type", only as many characters are copied from
the left as the output variable can hold. The special internal relay
R9009 (%MX0.900.9) is set.
The number of steps may vary depending on the PLC and parameters
used, see also Table of Code Intensive Instructions in the online help.
Data type I/O Function
STRING 1st input input string
INT 2nd input number of input string's characters that are copied, from the left
STRING output copied string
No. IEC address Set If
R9007 %MX0.900.7 permanently
R9008 %MX0.900.8 for an instant
input string is longer than the length
defined for the input variable in the field
"Type"
R9009 %MX0.900.9 for an instant output string is longer than the length
defined for the output variable in the field
"Type"
Description
LEFT copies, starting from the left, n characters of the string of the first input variable to the output
variable. You define the number of characters to be delivered n by the second input variable.
Data types
Error flags
Example
In this example, the same POU header is used for all programming languages. For an example
using IL (instruction list), please refer to the online help.
POU header
All input and output variables used for programming this function have been declared in the POU
header.
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