SPECIAL CARD INCREASING METHOD OF PLC

摘要

The method increases the number of special cards of a programmable logic controller (PLC) having a limited number of I/O cards to be expanded. The signal lines which connect plug connecters (F,F') of a special card are not twisted, and signals transmitted from a CPU is decoded to select general I/O cards or special cards so that the number of special card is increased not affecting the number of I/O cards.