Lenze PLC Designer PLC Designer (R2-x) - Manual (Page 333)

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DMS 3.2 EN 02/2011 TD29 331
'Extras' 'EN/ENO' in CFC
Symbol: Shortcut: +
This command is used to give a selected block (Cursor position 3) an additional
Boolean enable input EN (Enable In) and a Boolean output ENO (Enable Out).
ADD is only executed in this example when the Boolean variable "condition" is TRUE.
VarOut will also be set to TRUE after the execution of ADD. But if afterwords condition
changes to FALSE, ADD will not be executed any more and thus VarOut remains TRUE!
The example below shows how the value ENO can be used for further blocks:
x should initialised to 1 and y initialised to 0. The numbers in the right corner of the
block indicate the order in which the commands are executed.
x will be increased by one until it reaches the value 10. This causes the output of the
block LT(0) to deliver the value FALSE and SUB(3) and ADD(5) will be executed. x is set
back to the value 1 and y is increased by 1. LT(0) is executed again as long as x is
smaller than 10. y thus count the number of times x passes though the value range 1
to 10.