S7-GRAPH for S7-300/400 Programming Sequential Control Systems
C79000-G7076-C526-01
Glossary-1
Glossary
Action
An action is an instruction to execute a function when a step is active.
Alternative branch
An alternative branch is the divergence of a sequencer to one step of several
alternatives depending on several parallel transitions.
Checkpoint
The checkpoint is a point in the program cycle at which the plant states can be
queried or influenced. There are various checkpoints, for example:
•
System checkpoint (SCP)
•
User
checkpoint
Criteria analysis
Criteria analysis is a software program for S7-Graph consisting of criteria FBs and
extended instance DBs. The criteria analysis detects and influences plant states of
S7-Graph sequential control systems.
Deactivate
Deactivating means that the step is terminated by the corresponding transition or
by another step.
Edge evaluation
Edge evaluation is necessary to detect and evaluate the change in a signal state.
The term "edge" refers to a change in a signal state (for example at an input).
There is a rising edge when the signal state changes from "0" to "1". In the
opposite direction, the term falling edge is used.