ABB DCP02 programming controller
Safety InstructionsRead and follow the safety instructions given in this section before starting any work. However,
local statutory regulations, if stricter, are to take precedence.
The tension measurement system contains no moving parts. However, the load cells are
mounted close to a rotating roll over which a web is running.
1.6.1 Personnel Safety
WARNING
Never work with the load cells, or nearby, when the production line is in service.
Before starting any work, switch off and lock the operating switch of the drive
section for the measuring roll.
DANGER
Switch off and lock the mains operating switch to the tension electronics before
performing any work on the tension electronics. When the work is completed,
check that there are no loose wires, and that all units are properly secured.
NOTE
All personnel working with the installation must know the location of the main
power supply switch to the measurement system and how it is operated.
1.6.2 Equipment Safety
CAUTION
Always switch off the mains supply voltage to the measurement system before
replacing a unit.
CAUTION
Handle the electronic unit carefully to reduce the risk of damage from
Electric Static Discharge (ESD). Note the warning label on the circuit boards

The operating principle of a force transducer has a great effect on how well it will perform. It
also affects how stiff and vibration-free the entire load cell will be, as well its robustness and
tolerance to overload. All of these factors impact on the design, operation, and maintenance of
the web processing machinery.
ABB’s Pressductor® transducer technology produces a signal as a result of changes in an
electromagnetic field when the load cell is subjected to mechanical force. It is an operating
principle that has its origin in a metallurgical phenomenon according to which mechanical
forces alter the ability of some steels to convey a magnetic field. Unlike other types of load cell
technologies, physical movement such as compression, bending or stretching is not required for
signal generation.
A Pressductor® transducer (the sensor inside the load cell) is a simple and elegant design.
Essentially, two perpendicular windings of copper wire around a steel core combine to provide a
measurement signal.
An electromagnetic field is created by continuously feeding an alternating current to one of the
windings. The field is positioned in such a way that, since the windings are at right angles to
each other, there is no magnetic coupling between them when the load cell is unstressed.
However, when the transducer is subjected to a force, as shown in the figure, the magnetic field
pattern changes. A portion of the field couples with the second winding and induces an AC
voltage that reflects the tension exerted by the web on the measurement roll. This voltage - a
comparatively strong transducer signal - is converted by the load cell system’s tension
electronics into a system output.