Delta DVP-ES2 - Manual (Page 13)

1 . P L C C o n c e p ts
1 - 5
1.5 Ladder Logic Symbols
The following table displays list of WPLSoft symbols their description, command, and memory
registers that are able to use the symbol.
Ladder Diagram
Structure
Explanation Instruction Available Devices
NO (Normally Open)
contact / A contact
LD X, Y, M, S, T, C
NC (Normally Closed)
contact / B contact
LDI X, Y, M, S, T, C
NO contact in series AND X, Y, M, S, T, C
NC contact in series ANI X, Y, M, S, T, C
NO contact in parallel OR X, Y, M, S, T, C
NC contact in parallel ORI X, Y, M, S, T, C
Rising-edge trigger
switch
LDP X, Y, M, S, T, C
Falling-edge trigger
switch
LDF X, Y, M, S, T, C
Rising-edge trigger in
series
ANDP X, Y, M, S, T, C
Falling-edge trigger in
series
ANDF X, Y, M, S, T, C
Rising-edge trigger in
parallel
ORP X, Y, M, S, T, C
Falling-edge trigger in
parallel
ORF X, Y, M, S, T, C
Block in series ANB None
Block in parallel ORB None