Specifications

SIMATIC Instructions
9-12
S7-200 Programmable Controller System Manual
C79000-G7076-C233-01
Compare Double Word
The Compare Double Word instruction is used to
compare two values: IN1 to IN2. Comparisons include:
IN1 = IN2, IN1 >= IN2, IN1 <= IN2, IN1 > IN2,
IN1 < IN2, or IN1 <> IN2.
Double word comparisons are signed
(16#7FFFFFFF > 16#80000000).
In LAD, the contact is on when the comparison is true.
In FBD, the output is on when the comparison is true.
In STL, the instructions Load, AND, or OR a 1 with the
top of stack when the comparison is true.
Inputs/Outputs Operands Data Types
Inputs ID, QD, MD, SD, SMD, VD, LD, HC, AC, Constant, *VD, *AC, *LD DINT
Outputs (FBD) I, Q, M, SM, T, C, V, S, L, Power Flow BOOL
L
A
D
S
T
L
LDD= IN1, IN2
AD= IN1, IN2
OD= IN1, IN2
LDD>= IN1, IN2
AD>= IN1, IN2
OD>= IN1, IN2
LDD<= IN1, IN2
AD<= IN1, IN2
OD<= IN1, IN2
F
B
D
LDD<> IN1, IN2
AD<> IN1, IN2
OD<> IN1, IN2
LDD< IN1, IN2
AD< IN1, IN2
OD< IN1, IN2
LDD> IN1, IN2
AD> IN1, IN2
OD> IN1, IN2
IN1
==D
IN2
222 224
333
221
==D