PLC Data type:

Each program works with data. There are different types of data to match real world problem. For example a counter machine counts a number of objects (that can be 0 to n), on the other hand if we want to read pressure value from a pressure sensor that can be  for example  -20.5 bar to 200.01 bar. In this section we go through the different data types and it’s upper and lower range.

We shall consider all data types described in the IEC 61131-3 standard.

BOOL constants are the truth values TRUE (1) and FALSE (0).