Edge
Edge A "rising" edge marks the 0 1-change of a Boolean variable. Hence a "falling" edge is the 1 0-change.
EN/ENO
EN/ENO standard input EN (enable) and standard output ENO (enable out) laid down by IEC 61131-3 for blocks. By these in-/outputs blocks are activated or the activation is read.
Enumeration
Enumeration particular data type for the definition of integer values