Chapter 8 Logic Instructions
The instruction allows input parameters BiasN, In and BiasP to connect the variables of different
data types. When BiasN, In and BiasP are the variables of different data types, the calculation is
performed with the data type which can contain the range of the values of BiasN, In and BiasP. For
example, if the data type of BiasN is INT and the data types of In and BiasP are DINT, the data type
of Out is DINT.
The instruction allows the input parameters and the output parameter to connect the variables of
different data types. But the length of the data type of the output variable must contain the length of
the variables that the input parameters connect. Otherwise, an error will occur during the compiling
of the software.
Precautions for Correct Use
The input variables are not allowed to omit. An error will occur during the compiling of the software if
the input variables are omitted. But the output variable is allowed to omit.
When the value of BiasN is larger than BiasP, the instruction will still be executed normally.
Programming Example
The data types of ZONE_BiasN, ZONE_In and ZONE_BiasP are INT, INT and DINT and the data
type of Out1 is DINT. When ZONE_EN is TRUE, the value of Out1 is 0 if the values of ZONE_BiasN,
ZONE_In and ZONE_BiasP are 1, 0 and 100 as shown in the following table Variable 1. If the
values of ZONE_BiasN, ZONE_In and ZONE_BiasP are 2, 50 and 100, the value of Out1 is 150
(150 = 50 + 100) as shown in the following table Variable 2. If the values of ZONE_BiasN, ZONE_In
and ZONE_BiasP are 50, -10 and 100, the value of Out1 is 40 (40 = - 10 + 50) as shown in the
following table Variable 3.
Variable 1
Variable 2
ZONE_BiasN
INT 2
Variable 3
8-147