Each input or output instruction is assigned an address (shown below the instructions in Fig. 1, on page 22) indicating the location in the PLC memory where the state of that instruction is stored.

THE use of function blocks for programming of programmable logic controllers (PLCs) is gaining wider acceptance. Rather than the classic “contact and coil” representation of ladder diagram or relay ...

With this Function Block, “you’re taking away between 50 percent and 80 percent of the programming work for the machine builder,” says Kowal. For end-users, he adds, “you’re eliminating the need for a ...