S7-SoftPLC:Configuring PC hardware ports

Bytes, words and double words of the process image can be assigned to hardware I/O addresses here. Hardware addresses in the first 64k segment of the PC can be addressed only (ISA-bus). The process image of the inputs is refresh directly before the OB1 with the values from the input ports. At the end of the OB1 the values of the PIQ are written into the configured output ports. Additionally the peripheral inputs and peripheral outputs can be assigned to ports as well. These are refresh only, when using these addresses in the PLC-program.