Nematron Pointe Controller - Manual (Page 414)

Appendix C: Ladder Diagram Block Reference Pointe Controller User Guide
412
Functional Description
This block always passes the Enable input state (EN) through to the Enable Out
output state (ENO) without change; when EN becomes on, ENO is turned on, and
when EN becomes off, ENO is turned off.
When EN becomes on, the block function is executed: a sub-string of up to
specified Length (LEN) is extracted from the Input String (IN) and placed in the
Output String (OUT). The sub-string is extracted from the right end of IN.
For example:
IN: ‘Hello world. This is PointeControl.’
LEN: 8
OUT: ‘Control.’
The block function is executed every time the ladder is scanned , so long as EN
remains on. If EN becomes off, then OUT remains at its last calculated value until
EN becomes on and the block function is executed again.
Configuration Reference
The parameters of this block are described in the following table:
Param Name Config Var Type Description
EN Enable no - The state of the rung (off/on)
received from the left.
ENO Enable
Out no - The state of the rung (off/on)
passed to the right.
IN Input
String req String
Literal
The input string. Literals must be
enclosed in single quotes (‘ ’).
LEN Length req unsigned*
Numeric
The length (i.e., the number of
characters) of the sub-string to be
extracted.
OUT Output
String req String The result of extracting the sub-
string. The output is always NULL-
terminated.
* Any unsigned (UB, UW, UD) Input, Output, or Memory tag. For more information, see “ Defining
Input, Output, Memory tags ” on page 114 .
NOTE: If the configured length of the string variable assigned to OUT is smaller
than the result of the function, then the result is truncated to fit. No overflow
error is generated.