News for Factory Automation 1/2016

AS-Interface

AS-Interface replaces the conventional wiring technology on the sensor-

actuator level. It has established itself as the standard for cost-effective

signal transmission using the same cable for power and signals. World

wide, there are 35 million installed AS-Interface I/O devices/modules in

use, of which more than three million are safe I/O devices/modules. This

makes AS-Interface the leader among safe field communication systems.

Modules are always installed in the same manner, regardless of the con-

troller and higher-level fieldbus system: The module is placed on the flat

cable at any position and can be integrated in all common controllers.

Machinery and plant manufacturers can completely decouple the installa-

tion from the higher-level controller, which is to be connected later on.

This enables efficient production standards to be defined.

Up to PL e and SIL 3

How exactly is the KE4 used? The module has two inputs for rotary

encoders or linear measuring sensors that can be connected via a

TTL, SSI, or sin/cos interface. Two safe outputs and numerous safety

functions mean that the module can be used in safety-critical

applications. With paired encoders or with one safe encoder per axis

of rotation, the module satisfies the requirements of safety levels PL e

and SIL 3.

Pepperl+Fuchs offers a wide range of different products and technolo-

gies that can be connected to the KE4 module for positioning tasks.

These range from optical distance sensors such as the VDM100 –

which uses Pulse Ranging Technology – to rotary encoders and

even positioning via Data Matrix codes, as is done with the PCV, for

example.

Clear Safety Logic

Not only is the KE4 module able to control and monitor individual

machines and plant components; when used in combination with the

Safety Monitor, it offers a compact solution and can do much more:

“With the monitor, the user has the opportunity to monitor safe position

ranges and speeds from a remote location,” explains Kern. Eight

logical trip circuits offer a wide range of safety options. Safe position

ranges and speeds are parameterized using PC software, and the

configuration is stored on a memory card in the device. “This is a further

advantage: components can be replaced quickly and easily, reparame-

terization is not required,” says Kern. “This means that the safety logic

remains clear and decentralized even for larger and more complex

applications. This often means that a higher-level PLC is not required.”

The AS-Interface network enables flexible expansion of the compact

safety system without being restricted to any particular topology.