(1) TC
Description: X0 after 2s, Y0
(2) loss delay fault
Figure 3 power failure delays broken ladder diagram and sequence diagram
Note: when X0 is ON, the normally open contact closure, Y0 connected and self-preservation; when X0 is off, the timer start time delay when X0 when time reaches the time timer setting is removed, Y0 from ON to OFF, realize the loss of delay.
(3) the timer reset circuit
(4) attention to process analysis: X0 connect 1S,T0 ON,Y0–State output for the ON,T0 is ON the normally closed contact, T0,Y0 changed its status to OFF. When the X0 is ON, and after a scan cycle, repeat the previous state.
PLC ONE 