3 Fundamentals of press design

102 Fundamentals of press design
for workpiece handling and die changing, are programmed using
sequential programming methods. Where fast response times are called
for, the relevant PLC input signals are defined as interrupt inputs
which, as the name suggests, interrupt cyclically processed control software
functions and trigger a response program which responds to external
events in an extremely short time.
3.5.9 Future outlook
Fig. 3.5.6
PLC American
manufacturer
Programmable logic controllers are ideally suited to their respective
application as single-purpose systems. They are particularly well suited
for the processing of logic operations. The trend is towards equipping
systems with ever more extensive, cost-intensive processing capability.
Development of programming languages, on the other hand, has
slowed down almost to a halt. Programs are still being written in the
form of ladder diagrams and instruction lists, which are comparable to
Metal Forming Handbook / Schuler (c) Springer-Verlag Berlin Heidelberg 1998