Rockwell Automation 1760-xxxx Pico Controller User Manual - Manual (Page 157)

Publication 1760-UM001D-EN-P - September 2005
Retention 7-7
S/R Function
Task:
After a power failure, the lights in a stairwell should resume their
previous switching state. (This is another method to solve the same
task.)
Contacts and relays used:
Signal diagram:
U = Supply voltage
Coil Function
T2 Enable after first cycle
I1 Push-button
M1 Push-button pulse (rising edge detection)
M2 Pulse limitation (one shot)
Q1 Lamp output
M15 Impulse relay (retentive)
-----------TT2
I1-M2------{M1
--------{M2
M1-M15----SM15
M1-M15----RM15
M15-T2-----{Q1
RES
TRG
00.10
T2
+
X
S
{
I1
M1
M15
Q1
T2
t
U