Image Processing Reference
In-Depth Information
Amount of wires in a plant
1
Plant intranet
or internet
10
Control
network
100
Fieldbus
level
1,000
WISA
Machine and
device level
10,000
100,000
Sensors with integrated
AS-I-interface
Standard sensors,
actuators
FIGURE .
Automation hierarchy in factory automation, communication levels, and number of possible nodes
to be connected wirelessly.
like mobile operators, controller to controller communication, and the machine and device level. It
is obvious that especially in the machine- and device level a large number of wires and connectors
areoperatedinaharshenvironment.
Sensors and actuators in the machine and device level operating over wireless links:
•
Allow a very flexible installation, a significant advantage in many parts of the machine-
building industry, where often a custom or special purpose machine is built just once.
The installation and commissioning often starts already in parallel to the ongoing design
process.
•
Enable fully mobile operation of sensors and actuators.
•
Enable new sensor or actuator applications which would not be possible with wired
devices.
•
Avoid cable “wear and tear” problems.
•
Avoid costly and time-consuming integration of mechanical cable tracks/chains, slip-
rings, or similar mechanical elements.
In an automotive assembly plant, up to , input or output points (IO) may be wired and many
of the cables and connectors are subject to repeated movement or reconnection.
Wireless communication systems for the machine and device level in factory automation must
guarantee high reliability, and low and predictable delay of data transfer. The requirements in the
