Programming Actions and Conditions
S7-GRAPH for S7 300/400 Programming Sequential Control Systems
7-16
C79000-G7076-C526-01
Interlock
An interlock is a programmable condition for interlocking the step that influences
the execution of individual actions.
Interlock
Supervision
S1
Step1
V
C
T1
Trans1
I 2.3
I 2.5
C
S1 RC
L0 CALL
A1.0
FC10
V1 OFF
S_ALL
Step1
If the logic operation of the conditions is satisfied, the actions combined with
interlocks are executed.
If the logic operation of the conditions is not satisfied, there is a disturbance:
•
Actions combined with an interlock are not executed
•
An interlock error is signaled (event L1).
You program an interlock at the single step display level. A maximum of 32 Ladder
Logic/FBD elements can be programmed per interlock. The result of the operation
is managed automatically by the system.
A programmed interlock is indicated by the letter C following the step at all display
levels.
Note
If you program an interlock this is only used in the actions when their instructions
have been extended by the letter C.
Empty Interlock
An interlock without a condition (in other words without Ladder Logic or FBD
elements) behaves like a satisfied interlock.
Supervision
A supervision is a programmable condition for monitoring a step that influences the
way in which the sequencer switches from one step to the next.
Interlock
Supervision
S1
Step1
V
C
T1
Trans1
V
IN1
IN2
CMP
== I
S1 RC
L0 CALL
A1.0
FC10
V1 OFF
S_ALL
Step1