Rockwell Automation 1734-XXXX POINT I/O and ArmorPOINT I/O DeviceLogix User Manual - Manual (Page 79)

Publication 1734-UM015A-EN-E - November 2009
DeviceLogix Capabilities 77
Enable Line feature The Enable Line feature can be supported by each instruction type in the
Function Block Editor. When an instruction supports the Enable Line feature,
that particular instruction can only be executed when Enable Line is on;
otherwise, that instruction maintains the data from the last data scan. In this
manner, functions can be executed conditionally based on the state of the
Enable input. Under normal conditions, the Enable output will have the same
value as the input, passing the enable information to the next instruction.
Certain error conditions that occur within the processing of a function block
may cause the Enable output to go false.
If the Enable Line feature is used, EnableIn can be connected to an input I/O
tag or the output of another function block. The EnableIn input will retain the
value of the source that it is bound to.
If the Enable Line feature is not needed, the EnableIn input can use a constant
value which can be set on each instruction’s property page. By default, this
constant will allow execution of the function.