Contact-free and absolute:
The STAHLTRONIC WCS3 position encoding system
Do you want to position storage and retrieval machines,
lifts, traversing carriages or automatic cranes to the
millimeter? If you don’t want your conveying equipment
to lose its bearings even after a power cuts - then
the STAHLTRONIC WCS3 position encoding system is the
solution for positional measurement in your installation,
and combines two characteristics: contact-free and absolute.
Stunningly simple. Three system components are all you
need for exact positional measurement.
The code rail
The basic material for the code rail either stainless
steel or a synthetic laminate 70 mm high and 0.5 mm
thick. An irregular pattern of slots and webs representing
a sequential code is punched into it, the basis for
the WCS3’s main advantage: the ability to measure the
current position contact-free and absolute, independent
of reference points. Even after a power cut no reference
runs are necessary.
Ingenious devices are available for integrating the
code rail into your installation quickly and economically.
The reading head
The reading head has a U-shaped section. The open side
of the “U” is guided over the code rail free of contact,
scanning the code of the rail opto-electronically. A
micro-computer calculates from the pattern read the
current position of the reading head, and thus also
of the conveying equipment, to an accuracy of 0.5 mm.
Even lateral offset of up to ±13 mm, canting and travel
around bends do not disconcert the WCS3.
The position counts are transmitted directly to the
controls or the interface module via serial interfaces.
Continuous self-diagnosis ensures that the position
counts are always correct. The current operating condition
can be checked at any time by means of 3 LEDs on the
reading head. The data cable is connected via a 9-pole
D-SUB connector.
The interface module
The interface module is the interface between reading
head and control equipment. It reads the positional
information from the RS485 interface of the reading
head and converts it so that it can be read by any control
equipment. Up to 4 reading heads can be connected to
one interface module. The current position count of
the reading head is shown on a display. Tut the display
also helps you to find the cause of any fault by showing
a detailed error code. In addition, a remote diagnosis
of the optical unit of the reading head can be speedily
carried out via the interface module.
The following interfaces are available for connection to the control equipment:
- Parallel, binary or Gray
- Synchronous serial binary or Gray
- Profibus DP
- InterBus-S
- CANopen
Advantages of the WCS3
- contact-free absolute encoder for linear measurement
- no mechanical wear
- optimised for material handling applications
- continuous calculation of current position
- no reference points necessary
- resolution 0.5 mm
- reading section from 10 cm up to 300 m
- reading reliable up to a travel speed of 6 m/s
- automatically detects reading errors by means of self-diagnosis
- for straight and curved tracks, ring- and star-shaped
systems
- code rails only necessary in the positioning area
- code rail simple to attach
- display of position count and diagnosis in control cabinet
in connection with interface module
- diverse interfaces suitable for every type of control
- remote diagnosis for optical system of reading head via interface module.