Positive And Negative Edge Instructions - Siemens SIMATIC S7 System Manual

Instruction
6.1.1.2

Positive and negative edge instructions

Positive and Negative transition detectors
P contact: LAD
P coil: LAD
P_TRIG: LAD\FBD
Parameter
M_BIT
IN
OUT
CLK
Q
S7-1200 Programmable controller
System Manual, 11/2009, A5E02486680-02
S1 R
RS 0 0
0 1
1 0
1 1
S R1
SR 0 0
0 1
1 0
1 1
N contact: LAD
N coil: LAD
N_TRIG: LAD\FBD
Data type Description
Bool Memory bit in which the previous state of the input is saved
Bool Input bit whose transition edge is to be detected
Bool Output bit which indicates a transition edge was detected
Bool Power flow or input bit whose transition edge is to be detected
Bool Output which indicates an edge was detected
"OUT" bit
Previous state
0
1
1
Previous state
0
1
0
P box: FBD
P= box: FBD
Programming instructions
6.1 Basic instructions
N box: FBD
N= box: FBD
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