PIW and PQW are process channels, also called peripheral channels, which are not limited by the scanning period of PLC and can be input and output instantly. Note that the minimum transmission unit of procedures PI and PQ is bytes.
I area and Q area are often used for the input and output of digital quantities, and the smallest unit can be bits. PI and PQ areas are often used for analog input and output, and the minimum transmission unit is bytes.
The analog input and output addresses of 200PLC are AIW, AQW and IW, respectively, indicating the switching value I0.0-I 1.7.
The analog input and output addresses of 300PLC are PIW, PQW and IW, respectively, indicating the switching value I0.0-I 1.7.
PIW304 and IW304 are not the same address, and 304 is either an on-off address or an analog address, which cannot be duplicated. It is different from the 200 series with both IW0 and IW0, which is the difference between 200 and 300.