FMS CMGZ100 User manual

Operating Manual CMGZ100
Analog Tension Controller
Version 2.01 04/02 fg
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© by FMS Force Measuring Systems AG, CH-8154 Oberglatt – All Rights reserved..

Operating Manual CMGZ100
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1Safety instructions
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 or brakes 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.
Caution
Improper handling may damage the fragile electronic equipment! Don’t use rough tools as screwdrivers or
pliers! Touch earthed metal part to discharge static electricity before touching the electronic unit!
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.
Danger
Make sure the Tension Controller operates in the correct direction! If the Tension Controller operates the wrong
way, the drive tends to run immediately with maximum speed, causing damage (i.e. material cracking) or
personal injury! Check the Tension Controller behaviour by measuring the output value before power on the
drive!

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Table of contents
1 Safety instructions............................................................................................2
2 System Description...........................................................................................4
2.1 Block diagram 4
2.2 Function 4
2.3 Strain gauge amplifier 4
2.4 PID-Controller 4
2.5 Controller release 5
2.6 Limit switches 5
2.7 Overlaid line speed 5
3 Wiring diagram ................................................................................................6
4 View of the setting elements ............................................................................6
5 Operating the strain gauge amplifier.............................................................7
5.1 Calibrating the strain gauge amplifier 7
5.2 Lowpass filter 7
5.3 Setting the limit switches 7
6 Operating the PID controller..........................................................................8
6.1 Setting of the basic controller behaviour 8
6.2 Overlaying the line speed 8
6.3 Internal/external tension reference 8
6.4 Determining the control Parameters 8
7 Dimensions........................................................................................................9
8 Technical data...................................................................................................9

Operating Manual CMGZ100
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2System Description
2.1 Block diagram
The block diagram shows the strain gauge amplifier, the PID controller, the limit switches, the overlay of the
line speed and the power supply.
C100003e
2.2 Function
The CMGZ100 combines a strain gauge amplifier with a PID controller and is suitable for controlling the
material tension in machinges for finishing paper, plastic foils, aluminium foils, metal sheets, wires and most
other continuously processed materials.
The amplifier is based on reliable components from the FMS range and provides offset and gain adjustment as
well as an adjustable low-pass filter.
The Tension Controller provides independently adjustable Proportional, Integral and Derivative control blocks,
and can be released over a digital input that is operated with 24VDC or AC.
The Tension Controller also has also a minimum and a maximum limit switch with relay outputs.
The pcb is built to European standard size with DIN41612 F connector.
2.3 Strain gauge amplifier
The strain gauge amplifier is based on a hybrid module that provides the stable excitation voltage (5V) for max.
2 sensors with 350Ω. It amplifies the mV signal to 10V. Offset and gain are adjusted with the front-mounted 10-
turn potentiometers. The 10V signal is the feedback signal for the Tension Controller.
2.4 PID-Controller
The controller part calculates Proportional, Integral and Derivative values based on the difference between
reference and feedback.
The coefficients are independently adjustable over a wide range with potentiometers R6, R1 and R8..
The tension reference can be set using the internal potentiometer R5 or by changing jumper X20 to X21 and
using an external 100kΩpotentiometer.

Operating Manual CMGZ100
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2.5 Controller release
The CMGZ100 Tension Controller can be released over a digital input (12-30V AC or DC). As long as there is
no signal the Tension Controller is locked and the output is zero. When the voltage is applied the Tension
Controller starts operating and the output signal goes from zero to the required value that is needed for the
desired tension.
2.6 Limit switches
The CMGZ100 provides a minimum switch (GW1) and a maximum switch (GW2). If the threshold is overrun
the appropriate front-mounted LED lights up and a relay switches on (24V, 0.5A). The thresholds are being set
with front-mounted 10-turn potentiometers R3 ad R4.
The threshold value can be measured at pin X4 and X5.
The relay outputs are available on the connerctor at z14/z16 and d14/d16.
2.7 Overlaid line speed
If the Tension Controller is used in a line drive application the dynamic can be increased by using an available
line speed signal, which is fed to the Tension Controller. The tension control loop then is only responsible for
the correction of this signal. By setting jumper X24 to X25 the part of this overlaid controller signal can be
adjusted.

Operating Manual CMGZ100
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3Wiring diagram
C100004e
The force sensors are connected using 2x2x0.75mm2[AWG 18] shielded twisted pair cable. (With cable length
below 15m, 2x2x0.25mm2[AWG 23] is also suitable.)
The shield must be connected only to the Tension Controller side to aviod earth loops.
4View of the setting elements
C100001e

Operating Manual CMGZ100
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5Operating the strain gauge amplifier
5.1 Calibrating the strain gauge amplifier
•Connect first sensor.
•Test if feedback signal (z18) is positive when sensor is
loaded. If signal is negative, change z4 and z6.
•Connect second sensor
•Test if feedback signal (z18) is positive when sensor is
loaded. If signal is negative, change z4 and z6 of second
sensor.
•Insert material loosely into machine.
•Adjust feedback signal (z18) to zero with
potentiometerR1 (Offset).
•Load material with known weight as shown in the sketch
beside.
•Adjust feedback (z18) to required voltage at the loaded
weight with R2 (Gain).
5.2 Lowpass filter
The Tension Controller provides a first-order lowpass filter to eliminate noise coming from unbalanced rollers,
oscillations of the band material or similar.
The adjustment of the cutoff frequency is done by means of a non-polarized capacitor using the following table:
Setting the cutoff-frequency
The corresponding capacitor is chosen with the following formula or table:
C = 10 C: Capacity in Mikrofarad, F: Cutoff-frequency (3dB-Point)
F
Frequency in Hertz Capacitor in
Mikrofarad
1 10
2 5
5 2
10 1
20 0,5
50 0,2
100 0,1
200 0,05
500 0,02
1000 0,01
5.3 Setting the limit switches
The two limit switches are adjusted with built in potentiometers.
The minimum limit is adjusted with R3. The corresponding voltage can be measured at pin X4.
The maximum limit is adjusted with R4. The corresponding voltage can be measured at pin X5.
The voltages are compared with the tension feedback signal (z18).
C431011e
Table: Cutoff frequency of lowpass filter.
The filter is acting on the feedback signal.
The capacitor has to be soldered to pins X2 and X3.
Use non-polarized capacitors because positive and
negative voltages can occur at this point.

Operating Manual CMGZ100
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6Operating the PID controller
6.1 Setting of the basic controller behaviour
Depending on this setting, a feedback signal that is greater than the reference (negative error) creates a positive
output signal (Jumper X22, pos) or a negative output signal (Jumper X23, neg). The setting required depends
whether the application is a winder or unwinder or in the case of a line drive whether the controlled drive is
before or after the tension measuring roller.
Danger: Make sure the Tension Controller operates in the correct direction! If the Tension Controller operates
the wrong way, the drive tends to run immediately with maximum speed, causing damage (i.e. material
cracking) or personal injury! Check the Tension Controller behaviour by measuring the output value before
power on the drive!
6.2 Overlaying the line speed
In the case of a line drive if there is a 10V-signal available that is proportional to the line speed one can improve
the dynamics of the Tension Controller. Feed that signal to terminals d20/d22. The Tension Controller uses this
signal as predictive output signal and adds the calculated tension control output signal.
The tension control loop then only has to correct the synchronisation errors. Jumper X24 has to be set to X25.
Resistor R54 (pins X30 and 31) determines the percentage of the control output. R54 is chosen 10kΩas
standard giving 10%. The resistor value (in kΩ) gives the percentage.
With no line speed the Jumper has to be in position X24 to give exact 100%.
6.3 Internal/external tension reference
To use the internal potentiometer for the tension reference set Jumper X20. To use an external 100kΩ
potentiometer set jumper to X21. Connect external potentiometer to d2/d4/d6
6.4 Determining the control Parameters
•Connect control release to z12/d12
•Check the operating direction of the Tension Controller
without power on the drive. To do this the sensors can
be loaded with a force near the reference and the output
signal can be checked with a voltmeter at z20. The
Tension Controller must be released for this check.
•Turn potentiometer R6/R7/R8 anticlockwise
•Release controller
•Turn potentiometer R6 (Proportional) clockwise until
drive starts to oscillate. Turn back a little.
•Turn potentiometer R7 (Integral) to the right until drive
starts to oscillate. Turn back a little.
•If required for satisfying control results turn
potentiometer R8 (Derivative) clockwise until drive starts to oscillate. Turn back a little.
•If a scope is used the following sketch might be helpful
Notice: If the CMGZ100 has to control a winder or unwinder with varying bobbin diameters, the diameter of
the bobbin goes into the calculation of the controller coefficients. If the bobbin is full, the stability of the loop is
most critical as this is equal to a high control gain. A setting that allows stability ofver the whole range of the
diameter therefore has to be used at the largest diameter.
C431013e

Operating Manual CMGZ100
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7Dimensions
C100002e
8Technical data
Power supply 24VDC (18..36VDC) 3W
Excitation for strain gauges 5VDC max. 30mA for 2 pcs 350Ω-sensors
Analog output tension feedback ±10V max. 10mA short circuit proof
Controller analog output ±10V max. 10mA short circuit proof
Controller release isolated input 12–30V AC or DC
if input is inactive, integral part and output are set to zero
Limit switch 1 Minimum Adjustable with potentiometer corresponding to 0–10V tension
feedback, relay output 24V/0.5A; hysteresis 30mV
Limit switch 2 Maximum Adjustable with potentiometer corresponding to 0–10V tension
feedback, relay output 24V/0.5A; hysteresis 30mV
Connector DIN41612 type F rows d + z
Temperature range –10...+50°C [14...122°F]

Operating Manual CMGZ100
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