Siemens SIMATIC S7 - Page 231

Program instructions
7.4 Compare
S7-200 SMART
System Manual, V2.3, 07/2017, A5E03822230-AF
231
Selecting the data types to be compared
The data type identifier that you choose determines the required data type for the IN1 and
IN2 parameters.
Data type identifier
Required IN1, IN2 data type
B
Unsigned byte
W Signed word integer
D
Signed double word integer
R Signed real
LAD contacts, FBD boxes
STL
Comparison result
LDB= IN1, IN2
OB= IN1, IN2
AB= IN1, IN2
Compare two unsigned byte values:
The result is TRUE, if IN1 = IN2
LDW= IN1, IN2
OW= IN1, IN2
AW= IN1, IN2
Compare two signed integer values:
The result is TRUE, if IN1 = IN2
LDD= IN1, IN2
OD= IN1, IN2
AD= IN1, IN2
Compare two signed double integer values:
The result is TRUE, if IN1 = IN2
LDR= IN1, IN2
OR= IN1, IN2
AR= IN1, IN2
Compare two signed real values:
The result is TRUE, if IN1 = IN2