Siemens Simatic S7 Series

Program instructions
7.1 Bit logic
S7-200 SMART
158 System Manual, 09/2015, A5E03822230-AC
7.1.7
Coils: output and output immediate instructions
LAD
FBD
STL
Description
= bit
The Output instruction writes the new value for the output bit to the
process image register.
LAD
and
FBD
: When the output instruction is executed, the S7-200
turns the output bit in the process image register ON or OFF. The as-
signed bit is set equal to power flow state.
STL: The value on the top of the stack is copied to the assigned bit.
=I bit
The Output Immediate instruction writes the new value to both the
physical output and the corresponding process image register location
when the instruction is executed.
LAD
and
FBD
: When the output immediate instruction is executed, the
physical output point (bit) is immediately set equal to power flow. The
"I" indicates an immediate reference; the new value is written to both
the physical output point and the corresponding process image register
address. This differs from the non-immediate references, which only
write the new value to the process image register.
STL
: The instruction immediately copies the value on the top of the
stack to the assigned physical output bit and process image address.
Input / output
Data type
Operand
Bit
BOOL
I, Q, V, M, SM, S, T, C, L
Bit (immediate)
BOOL
Q
Input (LAD)
BOOL
Power flow
Input (FBD)
BOOL
I, Q, V, M, SM, S, T, C, L, Logic flow
See also
Bit logic output examples (Page 163)