FMS CMGZ434 User manual

Operating Manual CMGZ434
Digital microprocessor controlled tension control unit
for line drives
Version 2.22 05/04 sd
This operation manual is also available in german and french.
Please contact your local representative.
Diese Bedienungsanleitung ist auch in deutsch und französisch erhältlich.
Bitte kontaktieren Sie die Vertretung im zuständigen Land.
Ce mode d'emploi est également disponible en français et en allemand.
Veuillez contacter la représentation locale.
© by FMS Force Measuring Systems AG, CH-8154 Oberglatt – All rights reserved.

Operating Manual CMGZ434
2
1Safety Instructions
1.1 Description conditions
a) High danger of health injury or loss of life
Danger
This symbol refers to high risk for persons to get health injury or loss life. It has to be
followed strictly.
b) Risk of damage of machines
Caution
This symbol refers to informations, that, if ignored, could cause heavy mecanical damage.
This warning has to be followed absolutely.
c) Notice for proper function
Notice
This symbol refers to an important information about proper use. If not followed,
malfunction can be the result.
1.2 List of safety instructions
Proper function of the Tension Controller is only guaranteed with the recommended
application of the components. In case of other arrangement, heavy malfunction can be
the result. Therefore, the installation instructions on the following pages must be
followed strictly.
Local installation regulations are to preserve safety of electric equipment. They are not
taken into consideration by this operating manual. However, they have to be followed
strictly.
The tension controller can operate drives with high performance. It has no built-in
emergency stop function. To provide safety of man and machine in case of malfunction,
the person responsible for system design has to establish specific safety procedures such
as emergency stop ciruits, etc.
Bad earth connection may cause electric shock to persons, malfunction of the total
system or damage of the electronic unit! It is vital to ensure that proper earth connection
is done.
The processor board is mounted directly behind the operation panel. Improper handling
may damage the fragile electronic equipment! Don’t use rough tools as screwdrivers or
pliers! Don’t touch processor board! Touch earthed metal part to discharge static
electricity before removing operation panel!
Some contacts of the 110VAC resp. 230VAC version are under 110V resp. 230V
tension! Mortal danger! Disconnect power supply before open the housing!

Operating Manual CMGZ434
3
Table of contents
1 Safety Instructions............................................................................................2
1.1 Description conditions 2
1.2 List of safety instructions 2
2 Definitions .........................................................................................................4
3 System components..........................................................................................4
4 System description............................................................................................5
4.1 Functional description 5
4.2 Force sensors 5
4.3 Electronic unit CMGZ434 5
4.4 Drive 6
5 Controller theory..............................................................................................7
5.1 Tension control loops 7
5.2 PID controller 7
6 Quick installation guide...................................................................................8
7 Dimensions........................................................................................................9
7.1 Dimensions: Variant for insert card support block (CMGZ434) 9
7.2 Dimensions: Variant with separate housing (CMGZ434.E) 9
8 Installation and wiring...................................................................................10
8.1 Mounting and wiring of the electronic unit 10
8.2 Mounting the force sensors 11
8.3 Mounting the drive unit 11
8.4 Mounting the tacho generator 11
8.5 Wiringdiagram:Variant forinsert cardsupport block(CMGZ434) 12
8.6 Wiring diagram: Variant with separate housing (CMGZ434.E) 12
9 Operation ........................................................................................................14
9.1 View of the operating panel 14
9.2 Schematic diagram of main operating menu 15
9.3 Checking the parameters 15
9.4 Calibrating the measuring amplifier 16
9.5 Inputting the reference value 18
9.6 Definition of control parameters 18
9.7 Switching the control parameters 19
9.8 Automatic operation 20
9.9 Setup of line speed overlay 20
9.10 Additional settings 22
10 Serial interface (RS232)...............................................................................23
10.1 Wiring diagram: RS232 interface 23
10.2 Command list 24
10.3 Read parameter 24
10.4 Write parameter 25
11 Parametrization............................................................................................27
11.1 Parameter list 27
11.2 Schematic diagram of parametrization 28
11.3 Description of the parameters 29
12 Trouble shooting...........................................................................................38
13 Technical data CMGZ434...........................................................................39

Operating Manual CMGZ434
4
2Definitions
Offset: Correction value for compensation of the zero point difference. Thanks to the
offset, it is ensured that a force of 0N will generate a signal of 0V exactly.
Gain: Amplification factor for the measuring signal. Use of proper value will set the
measuring range of the sensor exactly corresponding to the signal output range (0...10V).
Strain gauge: Electronic component that will change its resistance while its length has
changed. Strain gauges are used in the FMS force sensors for acquisition of the feedback
value.
Single quadrant resp four-quadrant drive: Expression refers to the speed/torque
diagram used in the drive technology. A single quadrant drive can only drive in forward
direction; a four-quadrant drive can both drive and brake in forward and reward direction.
3System components
The FMS line drive controller consists of the following components (refer also to fig. 1):
Force sensors
•For mechanical/electrical conversion of the tension force
•Force measuring bearing
•Force measuring roller, Force measuring journal or Force measuring bearing block
Electronic unit CMGZ434
•For supplying of the force sensors and amplifying of the mV signal
•With integrated digital PI- or PID-controller to drive the drive unit
•Speed or torque control supported
•External line speed signal can be processed an added to the output value
•With operation panel for parametrization
•Interface RS232
•Interface CAN-Bus
•For mounting into insert card support block EMGZ555959 (by mounting into switch
cabinet)
•Mounted in separate housing (CMGZ434.E)
•Integrated power supply (by using separate housing)
•Supports connection of an external feedback display
Drive
•Speed or torque controlled drive
•AC or DC motor
•many different products are suitable
(Italic components as variant or option)

Operating Manual CMGZ434
5
4System description
fig. 1: Basic structure of a drive control system on a line drive application
C434001e
4.1 Functional description
The force sensors measure the tension force in the material and transmit the measuring
value as a mV signal to the electronic unit CMGZ434. The electronic unit amplifies the
mV signal and calculates the error to the reference value. If the material tension is too low
resp. too high, the drive will be driven slower resp. faster, depending on the drive being
mounted before or after the force sensors (fig. 1).
4.2 Force sensors
The force sensors are based on the flexion beam principle. The flexion is measured by
strain gauges and transmitted to the electronic unit as mV signal. Due to the wheatstone
wiring of the strain gauges, the measured value is according also to the power supply. So,
the force sensors are supplied from the CMGZ434 by a very accurate power supply.
4.3 Electronic unit CMGZ434
Common
The electronic unit contains a microprocessor to handle all calculations and
communications, the highly accurate sensor power supply and the signal amplifier for the
measuring value. As operation interface it provides 4 keys, 4 LED’s and a 2x16
characters display in the front of the electronic unit. All inputs are saved in an EEPROM.
The electronic unit has no jumpers or trimmers to keep most accurate long-time and
temperature stability.
There can be connected one or two force sensors to the electronic unit.

Operating Manual CMGZ434
6
Strain gauge amplifier
The strain gauge amplifier provides the highly accurate 4V power supply. 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, low-pass filter).
Controller
The control unit compares the reference value with the measured feedback value and
transmits the error to the controller configurable as PI or PID. The controller calculates
the output signal according to the difference. The output signal is provided as an analog
signal (0...10V / ±10V / 0...20mA / 4...20mA).
With a tacho generator or other source, a 0...10V signal proportional to the line speed can
be fed to the controller. This signal may be overlayed to the PID signal.
Interface
As standard, the electronic unit supports an RS232 interface. As an option, there is an
additional board with CAN-Bus interface available.
fig. 2: Block diagram of the electronic unit CMGZ434 C434002e
4.4 Drive
There can be used any AC or DC four-quadrant drive selected according to the required
dynamics.

Operating Manual CMGZ434
7
5Controller theory
5.1 Tension control loops
When manufacturing and processing foils, wires, ropes, paper and fabric sheets, it is
important that the product is under constant tension when guided across the rollers.
Tension may change when humidity, temperature, winding or unwinding diameters vary
or when the sheets are being printed, coated, glued or pressed. Tension is measured
constantly and maintained at the correct value with the FMS force measuring and control
system.
5.2 PID controller
The function of any control loop is to
maintain the feedback value exactly at the
level of the reference and to minimize the
influence of any interference on the control
loop. In addition, the control loop must be
stable under all operating conditions.
These aims can only be achieved if the
dynamic behaviour of the control loop is
adapted to the machine.
The PID controller used in the CMGZ434
calculates an output signal that corresponds
to the addition of „P“, „I“ and „D“
component. The „D“ component can be
skipped alternatively. Due to the digital design, the controller has an exactly reproducible
behaviour, because every parameter is known as an exact number which doesn’t drift away.
Due to that, it has high long-time and temperature stability. This feature also allows to
exchange an electronic unit without readjusting.
„P“ component
A controller with only a proportional component emits an output signal that is
proportional to the error.If the error is zero, the output signal also will be zero. A small
error only can create a small output signal which is not high enough to compensate the
complete error. That means, that a controller with only a proportional component will have a
steady error. The characteristic value of a „P“ controller is the proportional factor Xp.
„I“ component
A controller with an integral component adds the error to the output signal continuously
and emits this output signal. Due to that, the output signal will be enlarged or reduced
until the error is zero. This output signal is maintained until a new error occurs. The
integral component therefore allows zero error in steady state. The characteristic value of
an „I“ controller is the settling time Tn.
„D“ component
A controller with a differential component has an output signal proportional to the
changing speed of the error. If the error changes in a step, the output will show the
characteristic peak impulse. Therefore, a „D“ controller reacts even if only a small
controller error occurs. The characteristic value of a „D“ controller is the derivative
action time TV.
fig 3: Step response of a PID controller
C432003e

Operating Manual CMGZ434
8
6Quick installation guide
•Check all your requirements such as:
– Charateristics of the drive (signal level, max. power, etc.)?
– Controller output configuration (signal level)?
– Feedback output configuration (signal level)?
– Gain switching required?
– Line speed input required?
– Linking by interface etc.?
– Emergency stop procedures?
•Draw your final wiring diagram according to wiring diagrams (ref. to „8.5 Wiring
diagram variant for insert card support block“ / „8.6 Wiring diagram variant with
separate housing“). Don’t forget digital input „Controller enabled“
•Install and wire all components (ref.to „8. Installation and wiring“)
•Control unit: Parametrize and calibrate measuring amplifier (ref. to „9.4 Calibrating
the measuring amplifier“)
•Proceed a test run with low speed and low material tension:
– Input reference value (ref. to „9.5 Inputting the reference value“)
– Determine PID control parameters and set machine into operation (ref. to
„9.6 Definition of control parameters“)
•If required, setup the line speed overlay (ref. to „9.9 Setup of line speed overlay“)
•If required, do additional settings (ref. to „9.10 Additional settings“)
Notice
It may be that the PID control parameters determined during the test run are no longer
suitable for stable operation after setup of pilot control or increasing of material tension.
Therefore it is useful to adjust the control parameters until the machine runs stable at the
required reference values.
Notice
Starting and stopping of the machine takes increased requirements to any control loop.
For stable operating also in these phases, you have to pay special attention to the starting
resp. stopping behaviour of the whole machine. It is not enough to get stable operating
during normal operating conditions.

Operating Manual CMGZ434
9
7Dimensions
7.1 Dimensions: Variant for insert card support block (CMGZ434)
fig. 4: Dimensions of the variant using insert card support block (series CMGZ400).
The support block EMGZ555959 has to be ordered separately. C431006us
If the electronic unit should be mounted into a 19“ rack, a multipoint plug is used instead
of the support block.
7.2 Dimensions: Variant with separate housing (CMGZ434.E)
fig. 5: Dimensions of the variant using separate housing (Option, series CMGZ400.E)
C431003e

Operating Manual CMGZ434
10
8Installation and wiring
Caution
Proper function of the Tension Controller is only guaranteed with the recommended
application of the components. In case of other arrangement, heavy malfunction can be
the result. Therefore, the installation instructions on the following pages must be followed
strictly.
Caution
Local installation regulations are to preserve safety of electric equipment. They are not taken
into consideration by this operating manual. However, they have to be followed strictly.
Danger
The tension controller can operate drives with high performance. It has no built-in
emergency stop function. To provide safety of man and machine in case of malfunction,
the person responsible for system design has to establish specific safety procedures such
as emergency stop ciruits, etc.
8.1 Mounting and wiring of the electronic unit
Variant for insert card support block (CMGZ434)
The insert card support block can be mounted in a control cabinet. Wiring to the terminals
is done according to „8.5 Wiring diagram: Variant for insert card support block“ (fig. 6).
The electronic card then will be inserted into the insert block. It will be locked by a stop
hook (fig. 4).
Variant with separate housing (CMGZ434.E)
The housing can be mounted in a control cabinet or directly beside the machine. All
connections are led through glands to the screw terminals and connected according to
„8.6 Wiring diagram: Variant with separate housing“ (fig. 7 and 8).

Operating Manual CMGZ434
11
8.2 Mounting the force sensors
Mounting of the force sensors is done referring to the FMS Installation manual which is
delivered together with the force sensors.
Wiring to the terminals of the electronic unit is done according to wiring diagram (fig. 6
resp. 7).
Notice
Connecting the shield of the signal cable to the electronic unit and to the force sensor
may cause ground circuits which may interfere the measuring signal massively.
Malfunction can be the result. The shield should be connected only to the electronic unit.
On the „force sensor side“, the shield should stay open.
8.3 Mounting the drive unit
The motor and the drive power amplifier will be mounted according to manufacturer’s
specification. (If an AC drive unit is used, the energy produced in the motor while
braking must be led off to a brake resistor or equivalent.)
Connection of the power amplifier to the Tension Controller’s output terminal is done
according to the wiring diagram (fig. 6 resp. 7).
Danger
The tension controller can operate drives with high performance. It has no built-in
emergency stop function. To provide safety of man and machine in case of malfunction,
the person responsible for system design has to establish specific safety procedures such
as emergency stop ciruits, etc.
8.4 Mounting the tacho generator
If the control loop is operated with line speed overlay, the actual line speed has to be
transmitted to the electronic unit. For this purpose the actual line speed is detected with a
tacho generator and the line speed signal is fed to the analog line speed input (terminals
d6 / d8 resp. 7 / 8).
The tacho generator is mounted according to manufacturer’s specification.
A other 0...10V signal proportional to the line speed may be used too (for ex. from a
PLC) instead of the tacho generator

Operating Manual CMGZ434
12
8.5 Wiring diagram: Variant for insert card support block (CMGZ434)
fig. 6: Wiring diagram: Variant for insert card suppor block C434005e
Caution
Bad earth connection may cause electric shock to persons, malfunction of the total system or
damage of the electronic unit! It is vital to ensure that proper earth connection is done.
8.6 Wiring diagram: Variant with separate housing (CMGZ434.E)
The housing of the electronic unit will be opened by unscrewing the 4 philips screws on
the operation panel and swinging out the operation panel to the right side.
Caution
The processor board is mounted directly behind the operation panel. Improper handling
may damage the fragile electronic equipment! Don’t use rough tools as screwdrivers or
pliers! Don’t touch processor board! Touch earthed metal part to discharge static
electricity before removing operation panel!
Danger
Some contacts of the 110V resp. 230VAC version are under 110V resp. 230V tension!
Mortal danger! Disconnect power supply before open the housing!

Operating Manual CMGZ434
13
fig. 7: Wiring diagram: Variant with separate housing C434011e
fig. 8: Screw terminal arrangement on Terminal board C432007e

Operating Manual CMGZ434
14
9Operation
9.1 View of the operating panel
fig. 9: Operating panel: Variant for insert card support block (CMGZ434) C434006e
fig. 10: Operating panel: Variant with separate housing (CMGZ434.E) C434007e

Operating Manual CMGZ434
15
9.2 Schematic diagram of main operating menu
fig. 11 C434008e
9.3 Checking the parameters
Before the initial setup is done, the following parameters have to be set resp. you have to
check if they correspond with the effective machine conditions (ref. to „11.
Parametrization“):
Measuring amplifier parameters
•Nominal force
•Unit of force
•Sensitivity
•1 or 2 sensors
PID controller parameters
•Lowpass output (reset to default)
•Line speed overlay (for the time being set to None)
•PID-configuration (for the time being set to PI; if PID configuration is required, refer
to „9.10 Additional Settings“)
•Output limit (set according to the drive used)
•Output configuration (set according to the drive used)
•Position line drive (depending on machine configuration)
•Ramp reference (reset to default)
•Reference (depending on machine configuration)
•Scale ref. input (if reference potentiometer is used)

Operating Manual CMGZ434
16
9.4 Calibrating the measuring amplifier
Simulating Method (recommended)
The following instructions are referring to
a setup and calibration on-site. The
material tension will be simulated by a
weight (fig. 12).
•Connect the first force sensor
•Check, if a positive value is displayed
when loading the sensor in measuring
direction. If not, exchange terminals
z6 / z8 (resp. 2 / 3)
•If used, connect the second force
sensor
•Check, if a positive value is displayed
when loading the sensor in measuring
direction. If not, exchange terminals
z6 / z8 (resp. 2 / 3)
•Insert material or a rope loosely to the machine
•Adjust offset by activating the parameter function find offset and pressing the ↵key
for 3 seconds. The electronic unit calculates automatically the new offset value.
•Load material or rope with a defined weight (fig. 12)
•Activate parameter function calibrate feedback. Input the force referring to the applied
weight (refer to „10. Parametrization“). The electronic unit calculates automatically
the new gain value.
•Quit calibration with Home key.
fig. 12: Calibrating the measuring
amplifier C431011e

Operating Manual CMGZ434
17
Mathematical method
If the material tension cannot be simulated, calibration has to be done by calculation. This
way of calibrating is less accurate because the exact angles are often unknown and the
effective mounting conditions, which usually deviate from the ideal, are not taken into
account.
•Offset adjustment has to be done as described under „Simulating method“.
•The Gain value will be calculated by the following formula and then inputted in the
parameter gain feedback (refer to „10. Parametrization“).
fig. 13: Force vectors in the FMS force measuring bearing C431012e
Definition of symbols:
αangle between vertical and measuring
web axis FBmaterial tension
βangle between vertical and FMF
Groller weight
γwrap angle of material FMmeasuring force resulting from FB
γ1entry angle of material FMeff effective measuring force
γ2exit angle of material n number of force sensors
δAngle between measuring web axis and FM
()
GainFeedback n =⋅⋅
1
2sin sin /
δγ

Operating Manual CMGZ434
18
9.5 Inputting the reference value
The material tension reference value can be inputted by the operating panel resp. interface,
or by the analog input:
reference input by operating panel resp. interface
•Set parameter reference internal / external to internal
•Press „REFERENCE“ key in the main operating menu for 3 seconds (refer to fig. 11).
Input new reference value using the keyboard. Quit change mode and save the new
reference in the EEPROM by using the ↵key. (If change mode is quit by using
„HOME“ key, the new reference is taken only into RAM and will be lost while power-
off or changing a parameter.)
•Alternatively: Send reference value by interface to the electronic unit (refer to „10.
Serial interface“).
reference input by analog input
•Set parameter reference internal / external to external
•Apply 0...10V source to the analog input (terminals z2 / d2 resp. 10 / 11)
•Set parameter scale ref. input to the needed reference value range (refer to „10.
Parametrization)
9.6 Definition of control parameters
Experimental determination of control parameters (recommended)
If the behaviour of the control loop is
unknown, tuning is done by means of a
systematic approach (fig. 14):
•Set parameter Derivative D to 0s (only
if PID configuration is used)
•Set parameter Integral I very high
(100.00s)
•Set parameter Proportional P very
small (for ex. 1.00)
•Enable controller
•If control loop is not oscillating:
Increase Proportional P
•If control loop is oscillating: decrease
Proportional P
•Repeat this procedure until the control loop is stable and nearly oscillating. The
controller can remain enabled; the controller parameters may be changed during
automatic operation.
•If the control loop is running stable with the „P“ component, the Integral I can be
decreased until the steady error disappears.
•If the Integral I is too small, the control loop will become unstable again.
•(Only using PID configuration): Increase Derivative D carefully until the controller is
nearly oscillating.
•If the Derivative D is too high, the control loop will become unstable again.
•If the control loop is running stable, the parameters Proportional P, Integral I and
Derivative D should be noted for eventually re-setup.
fig. 14: Transient effect of the control
system C431013e

Operating Manual CMGZ434
19
Mathematic determination of control parameters
•If the behaviour of the control loop is known, the control parameters may be
calculated by the known mathematical procedures and saved in the parameters
Proportional P0...P3, Integral I0...I3 resp. Derivative D0...D3. (There is only the
parameter set active which is chosen by the BCD inputs; refer to „9.7 Switching the
controller parameters“.)
•If the control loop is oscillating, the control parameters will be fine-tuned as described
under „Experimental determination of control parameters“.
Notice
There can be saved 4 different P-, I- and D- values (P0...P3; I0...I3; D0...D3). This allows
easy and flexible adjustment of the controller to different materials. (There is only the
parameter set active which is chosen by the BCD inputs; refer to „9.7 Switching the
controller parameters“.) The instructions above is valid for all 4 sets of parameters. But
for better understanding, the instruction is written in common form.
Notice
Correct setting of the control loop can be difficult. To judge the adjustment of the control
parameters, an oscilloscope may be helpful to record the behaviour of the feedback value.
The oscilloscope shows if the control loop operates stable, and if there is no more static
error.
Notice
The controller must be adjusted so that the feedback reaches the reference in the shortest
possible way but without overshooting. If the feedback overshoots, this is seen on the
display or with an oscilloscope.
9.7 Switching the control parameters
There can be saved 4 different P-, I- and D- values (P0...P3; I0...I3; D0...D3). Due to that,
it is possible to adjust the control loop flexibly to different material characteristics.
However, switching to another set of parameters is only possible if the controller is
disabled.
Switching is done by using the digital inputs „BCD cipher 0“ and „BCD cipher 1“
according to table below:
dig. input
BCD cipher 1 dig. input BCD cipher 0 Binary code BCD code Parameter set
open open 0 0 0 P0 / I0 / D0
open 24VDC 0 1 1 P1 / I1 / D1
24VDC open 1 0 2 P2 / I2 / D2
24VDC 24VDC 1 1 3 P3 / I3 / D3

Operating Manual CMGZ434
20
9.8 Automatic operation
State „Controller disabled“
After power on, the controller is disabled. Its output value is 0V, 0mA or 4mA
(depending on setting of parameter Output config.)
Enable controller
The controller will be enabled by digital input „Controller enabled“ or by serial interface.
The controller then begins to control the material tension and to hold it at the level of the
reference value, and the digital output „Controller ok“ will be activated.
Change of control parameters while automatic operation
The control parameters P0...P3 / I0...I3 / D0...D3, Influence of PI and PID-configuration
can be changed while the controller being enabled. Setting is done as written in „11.3
Description of the parameters“. The new values are taken for the control loop when
parameter mode is quit.
Change of reference value while automatic operation
The reference value can be changed while automatic operation as described under „9.5
Inputting the reference value“.
Disable controller
To terminate controlling after stopping the machine, the controller has to be disabled. If
enabling was done by interface, disabling must be done also by interface. After disabling
the controller, the output value will be set to zero immediately and the digital output
„Controller ok“ will be cancelled.
Notice
If the controller is disabled while the material is running, the drive unit will stop
immediately. This may cause material crack. Therefore, the controller should be disabled
only if the machine is no longer running.
9.9 Setup of line speed overlay
If the control unit is operated with line speed overlay, a line speed signal is used to build
the output value. The control unit adapts the signal referring to the diameter proportion
between tacho roller and drive roller. The hereby calculated value is taken and the
percentage quota of the PI resp. PID controller is overlayed. The sum will be the output
value. Therefore the controller now is only responsible for the non-synchronous part.
This will increase controlling stability.
The parameters for line speed overlay may be calculated. But often the referring values of
the machine are unknown. Therefore the experimental setup of line speed overlay is listed
below:
Transmission of line speed signal
To transmit the actual line speed to the electronic unit, an analog signal 0...10V (from a
tacho generator or other source) is fed to the analog input (terminals d6 / d8 resp. 7 / 8;
refer to „8.4 Mounting the tacho generator“)