ESP-DDS2-P (DDS Professional 2.0)
ESP-DDS2-PU1 (DDS Professional 2.0 Upgrade)
Function description
When using constants the smallest data type possible is used generally. The constant can be provided with a prefix type in order to change its data type. DINT#1 corresponds to the constant value 1 with a data type size of 4 bytes (Double Integer).
Applications
The prefix type is used e.g. in case of feedbacks in the CFC editor as shown in the picture below.
In the first drawing the integer variable nValue counts from –128 to 127. The ADD operator calculates within the value range of its inputs. In this case it is constant 1 with a data type size of 1 byte.
In the second example constant 1 is declared as integer through the prefix type. As a result, the ADD operator calculates within the integer value range. Therefore, variable nValue1 assumes values between –32768 and 32767.