F_IOPortRead

Most times a digital I/O port is a one byte wide I/O Position, which is mapped in the memory or as port. If you write a value at this place, the electrical signal at the output pins is changed according to the written bits.If you read a value from the input positon, the current logistic level is returned at the input pins as individual bit values.

The function F_IOPortRead reads a one eSize wide I/O position. The read value is returned from the function as return value. See description of the function  F_IOPortWrite

VAR_INPUT
    nAddr : UDINT;
    eSize : E_IOAccessSize;
END_VAR