Siemens SIMATIC S7-200 System Manual page 86

S7-200 Programmable Controller System Manual
Example: Contact Instructions
Timing Diagram
Network 1
Network 2
Network 3
72
Network 1
LD I0.0
A I0.1
= Q0.0
NOT
= Q0.1
Network 2
LD I0.2
ON I0.3
= Q0.2
Network 3
LD I0.4
LPS
EU
S Q0.3, 1
= Q0.4
LPP
ED
R Q0.3, 1
= Q0.5
I0.0
I0.1
Q0.0
Q0.1
I0.2
I0.3
Q0.2
I0.4
Q0.3
Q0.4
Q0.5
//N.O. contacts I0.0 AND I0.1 must be on
//(closed) to activate Q0.0. The NOT
//instruction acts as an inverter. In RUN
// mode, Q0.0 and Q0.1 have opposite logic states.
//N.O. contact I0.2 must be on or N.C.
//contact I0.3 must be off to activate Q0.2.
// One or more parallel LAD branches
//(OR logic inputs) must be true to make
//the output active.
//A positive Edge Up input on a P contact
//or a negative Edge Down input on a N contact
//outputs a pulse with a 1 scan cycle
//duration. In RUN mode, the pulsed state
//changes of Q0.4 and Q0.5 are too fast to
// be visible in program status view.
//The Set and Reset outputs latch the
// pulse in Q0.3 and make the state
//change visible in program status view.
On for one scan
On for one scan