Page 30 - 4587

Hardwired circuit (real I/O)

Figure 2 illustrates the hardwired circuit with the real inputs and
outputs circled. The devices that are not circled are implemented
inside the PLC through the programming of internal instructions.

Figure 5.2 - Real inputs and outputs to the PLC

Figure 5.3 illustrates the PLC implementation of the reduced-
voltage start circuit. The first line of the PLC program traps the
timer with internal output 1000. Contacts from this internal replace
the instantaneous timer contacts specified in the hardwired control

29