26
When constructing a failsafe circuit using ondelay timers only
Internal program
SM412
T1
On-delay timer
1s
M1
YB0
YB0
0.5s
0.5s
CPU module
Output module
L
L
MC
T1
24VDC
YB1
YBF
24V
0V
T2
On-delay timer
1s
M2
T2
M1
M1
M2
M2
MC
Externai load
YB0
*1
+
-
to
to
*1: Use a solid state relay for the M1 relay.