Operating Manual CMGZ 622
8
4.3
Electronic Unit CMGZ622
Common
The electronic unit is mounted to a robust aluminium housing. It contains a
microprocessor to handle all calculations and communications, the highly accurate
sensor power supply and the signal amplifiers for the measuring values of a measuring
point. The electronic unit has no trimmers and only few jumpers to keep most accurate
long-time and temperature stability.
Operation
The large backlit display with 2x16 characters, 4 LED’s and large keys guarantee
simple operation. All information is in plain text with the following languages
selectable: English, German, French and Italian. Most of the functions may be
paramterized. The parametrization can be done via the keys or the interfaces. All
inputs are fail-safe stored in an EEPROM. Additional settings can be made with
jumpers or solder bridges.
Strain gauge amplifier
The strain gauge amplifier provides the highly accurate power supply (5VDC or
10VDC) for 1 or 2 force sensors per measuring point. The force sensors can be wired
using 4 wire circuit or 6 wire circuit. This allows accurate control of the bridge
excitation even with very long cabling.
The power supply is equipped with current control. This allows detecting of short
circuit or cables break automatically and to output an error message if required.
A highly accurate, fixed difference amplifier rises the mV signal up to 10V. This
signal will be fed to the A/D converter. The microprocessor then does all application
specific calculations with the digitized measuring value (such as offset, gain, lowpass
filter, limit switches, etc). The resulting feedback value is provided as both tension and
current signal at the same time.
PID Controller
The control unit compares the reference value with the measured feedback value and
transmits the error to the PID controller. The PID controller calculates the output
signal according to the difference. The output signal is 0...10V, ±10V, 0...20mA or
4...20mA, depending on configuration.
With a diameter sensor or other source, a 0...10V signal proportional to the actual reel
diameter can be fed to the controller. Driving a winder, the controller calculates the
pilot control resulting from this signal and the actual output value. The PID values are
adjusted dynamically according to the changing reel diameter.
With a tachometer generator or other source, a 0...10V signal proportional to the line
speed can be fed to the controller. Driving a line drive, the controller takes the line
speed signal as a base to which the PID signal is overlaid. Therefore the controller
must only control the deviation to the line speed.
Interface
(To be developed) As an option there are RS232, PROFIBUS or CAN-Bus interfaces
available.
