REO REOVIB series System manual

REOVIB
Control units for flexible automation
Hand book for installing and setting up
REOVIB controllers
Concepts, questions and background information

Contents
1.0 General information about the REOVIB product range........................................................................ 1
2.0 Background to feed engineering ........................................................................................................... 2
2.1 The vibration wave form .....................................................................................................................2
2.2 The feed waveform .............................................................................................................................3
2.3 Vibrating frequency and resonance....................................................................................................3
2.3.1 Resonant condition ......................................................................................................................4
2.3.2 Under critical operation ................................................................................................................4
2.3.3 Over critical operation ..................................................................................................................4
3.0 Operating methods for vibratory feeders................................................................................................4
3.1 Unregulated drive control....................................................................................................................4
3.2 Regulated drive control.......................................................................................................................5
4.0 REOVIB – Symbols ................................................................................................................................5
5.0 REOVIB – Terms................................................................................................................................. 6
6.0 Functions of controls units.................................................................................................................... 8
6.1 Enable input or Stop/Start input..........................................................................................................8
6.2 Status output.......................................................................................................................................8
6.3 Soft start .............................................................................................................................................8
6.4 Soft stop..............................................................................................................................................8
6.5 Coarse/fine control..............................................................................................................................8
6.6 Air valve output ...................................................................................................................................8
6.7 Pulsed operation.................................................................................................................................8
6.8 Track control .......................................................................................................................................9
6.8.1 Single point control.......................................................................................................................9
6.8.2 Min/Max Control .........................................................................................................................10
6.8.3 Sensor Time-out.........................................................................................................................10
7.0 Controls ................................................................................................................................................11
7.1 Analogue units..................................................................................................................................11
7.2 Digital units .......................................................................................................................................11
7.2.1 Three key control panel..............................................................................................................11
7.2.2 Reset set point to zero ...............................................................................................................12
7.2.3 Six key control panel..................................................................................................................12
8.0 General manufactures instructions for the installation of REOVIB control units ..................................13
8.1 Before installation .............................................................................................................................14
8.1.0 Connection diagram for frequency drives ..................................................................................14
8.1.1 Setting the mechanical vibrating frequency 14
8.2 Setting the feeder throughput ...........................................................................................................15
9.0 Setting up regulation control of frequency ...........................................................................................15
9.0.1 Setup menu for regulation control..............................................................................................16
9.1 Relationship between acceleration and amplitude ...........................................................................16
9.2 Setting up instruction for using a controller in regulation mode ........................................................17
9.3 Determine resonant frequency .........................................................................................................17
9.3.1 Manual setting of the vibrating frequency ..................................................................................17
9.3.2 Automatic frequency search.......................................................................................................17
9.4. Optimizing regulation .......................................................................................................................17
9.4.1 Control range adjustment...........................................................................................................17
9.4.2 Optimizing the regulation circuit.................................................................................................17
9.5 Diagnostic displays for non-optimized regulation settings................................................................18
10.0 Working frequency of the coil.............................................................................................................18
11.0 Measurement of output current and voltage.......................................................................................18
12.0 Accelerometer mounting ....................................................................................................................18
13.0 Trouble shooting - analogue controllers .............................................................................................19
14.0 Trouble shooting - frequency controllers ............................................................................................20

1.0 General information about the REOVIB product range
The REOVIB range from REO ELEKTRONIK AG comprises all equipment produced for vibratory feeder
engineering. This includes controllers for vibratory feeders, measuring and monitoring equipment, with corre-
sponding transducers.
All types of feeder control units are available, using thyristors or triacs with phase-angle control or the newer
technique employing a frequency inverter. There are free-standing or panel-mounting versions, with many
variations to choose from and integrated functions for controlling product flow, depending on the unit type.
In most instances the product throughput is set by using a front-panel potentiometer or the user display but
the panel mounted units have inputs provided for an external, throughput set-point source from a 0…10V
signal voltage, 0(4)…20mA signal current or a potentiometer.
Control signals inputs, e.g. Start/Stop (Enable), or for sensors, e.g. track control, are usually brought out to
connectors in the case of enclosed units, or to terminals where panel-mounted versions are concerned.
REOVIB thyristor or triac controllers provide step-less adjustment or regulation of the feeder throughput
setting by varying the output voltage. The vibrating frequency is always dependent on mains frequency be-
cause thyristors and triacs can only influence the available supply half-wave (phase-angle control). When
only one half of the mains sine wave is selected the feeder vibrates at the same frequency as mains fre-
quency and when both halves are used the feeder vibrates at twice that of mains frequency. Using one half
of the mains sine wave is referred to as half-wave operation or 3000 vibrations/min (for a mains frequency of
50Hz). The use of both halves of the mains sine wave is called full-wave operation or 6000 vibrations/min
(for a mains frequency of 50Hz). A 60Hz supply correspondingly gives 3600 and 7200 vibrations/min.
REOVIB control units are equally suitable for operating with either frequency and can be set, by using a link
switch, to match the feeder frequency.
REOVIB Frequency inverter specially developed for use with vibratory feeders provides a highly stable,
drive frequency, independent of the supply frequency, tuned to that of the feeder and adjustable in 0.1Hz
steps. It is said by feeder manufacturers that the mechanical performance compares with that of mains fre-
quency. After assembly, using standard spring packs and components, the feed system can be electronically
fine-tuned to give optimum performance. The controller seeks for the resonant frequency of the feed system,
at a comfortable feed level, using a patented method, and then saves this in memory for future use.
Throughput setting of the feeder is achieved by using the variable output voltage of the controller. The am-
plitude is held constant whilst the controller is working in regulation mode thus compensating for widely
varying loads, caused by high and low product levels. The amplitude feedback signal is generated from an
accelerometer, fitted onto the feeder. A further advantage is gained through energy saving because the in-
coming mains power is reduced to 1/3 of that used by previous controllers. The feeders also run much
quieter and component orientation is more efficient because of the sinusoidal output current. In addition to
easy control of the feeder, other functions such as track and sensor control are integrated into the control
unit. Input and output ports are available for interlocking with other units or a supervisory system. The touch-
panel and display are user-friendly and allow settings to be made accurately and repeatable. User settings
can be saved and recalled.
REOVIB measurement and monitoring units comprise simple instruments for controlling the vibration
waveform (converts signal to 0…100% display), or units used for maximum and minimum limit monitoring.
An accelerometer is fitted onto the feeder to provide a feedback signal.
1

2.0 Background to feed engineering
The use of mechanical vibrators for feeding material, dosing, screening or mixing of goods is long estab-
lished. Drives, with so called out-of-balance motors and vibrating equipment with electromagnetic drives are
certainly the most widely applied. Electromagnetic drives are more frequently used in automation engineer-
ing and hence some fundamental differences require further explanation. In general one is referring here to
vibratory feeders.
Vibratory feeders comprise the actual drive unit, including one or more coils, a reaction base, a spring sys-
tem and tooling, which can be in the form of a tray, tube, track or a bowl with a spiral track inside. Tray
shaped vibratory feeders that deflect in one direction, are used to convey material and are generally referred
to as “Linear Feeders“. Vibratory feeders with a spiral track and a spring/coil combination that gives a com-
posite motion that are used for sorting, orientating and feeding parts, are known as “Bowl Feeders“.
2.1 The vibration wave form
The vibratory motion in the case of a vibratory feeder moves backwards and forwards in a straight line. The
direction of movement is at a specific angle relative to horizontal, referred to as the “vibrating angle“. The
movement plotted against a time axis gives a curve approaching the shape of a sine wave.
s Deflection
a Acceleration
v Speed
Diagram 1 The vibration curve
The sinusoidal waveform is derived from the formula
[mm]
where “s“ is the time based vibration movement, s0the amplitude (half of the total deflection) and ωthe cycle
frequency (2 πf ).
The vibrating speed is derived from the differential of deflection over time
with
the acceleration
with
2
tss ω sin
0
=
ts
dt
ds
v ωω cos
0
==
ω
00 sv =
ts
dt
ds
a ωω sin
2
0
2
2
−==
2
00
ω sa =
S
a
v
S,a,v
Sn
t
a0
s0
v0

2.2 The feed wave form
Diagram 2 shows a vibratory drive unit with a unidirectional deflection (linear feeder). The direction of move-
ment is determined by the vibrating angle. The material on the track is accelerated along the deflection path.
Diagram 2
The product describes a trajectory on the track (micro throw principle) which is determined by the vertical
component of the vibration acceleration exceeding that of the basic acceleration. The product lifts off the
feed track during forward movement, follows the trajectory over the time period tF(see diagram 3), meets the
feed track again, where it remains for a time period tB, in contact with the feed track until the cycle starts
again. The trajectory is so small and fast that it cannot be discerned with the naked eye.
tFTrajectory time
tBContact time
sf Product movement
s Deflection
a Acceleration
v Speed
Diagram 3 Trajectory path of the product
In practice, the feeder throughput is of particular interest. This is dependent on the horizontal component of
the vibrating speed of the feeder during the contact time tBand because the take-off point does not coincide
with the highest horizontal speed, the product speed never reaches that of the vibrating speed. The achiev-
able feeder throughput is different for each product and depends on the vibrating frequency and amplitude.
An increase of the feeder throughput cannot be achieved by adjustment amplitude alone; the correct vibrat-
ing frequency must also be selected for the product.
2.3 Vibrating frequency and resonance
Every vibratory system has a resonant frequency, which relates to its mass, spring constant and product
weight. If a feeder could be driven at resonance, in theory the amplitude is infinite and the system would be
uncontrollable. In practice such a condition cannot be achieved without something extra. Mechanical reso-
nance, however, displays a very specific characteristic and so the vibrating frequency of a feeder cannot be
too far away from resonance, otherwise the achieved deflection would be negligible. Furthermore, a damped
system, working at resonance, is not viable because every change of the damping caused by the product
would result in a change of the amplitude and hence the feeders throughput.
Conversely, operating at resonance also offers some advantages. The energy usage is greatly reduced and
the vibration movement becomes much more harmonic (sinusoidal), which results in a much quieter opera-
tion. Modern drive controllers such as the REOVIB MFS range constantly monitor the vibration movement
and provide a regulated operation, whereby the vibrating frequency is maintained at resonance and ampli-
tude is held constant.
3
S
sf
a v
tFtB
S,a,v,sf
t
sf
Trajectory
Vibrating angle α

2.3.1 Resonant condition
Diagram 4 shows various resonance curves for a feeder with different damping levels. This demonstrates the
relationship between damping and the shift in resonant frequency.
a = without damping (theoretical).
b – d = increasing damping levels.
fa= drive frequency.
fres = resonant frequency
fres > fa= under critical operation
fres < fa= over critical operation
Diagram 4
One can see from the curves that the resonant frequency of the vibrating system reduces with increased
damping. Different feeder drive characteristics can be achieved by tuning the vibratory system to a value
above or below the drive frequency. In practice both possibilities can be applied.
2.3.2 Under-critical operation
For under-critical operation the drive frequency fais lower than the resonant frequency fres. When the damp-
ing increases, by loading the feeder, the resonant frequency gets closer to the drive frequency. In this way
the system compensates itself and is unaffected by load changes. The power and the deflection run in phase
in this drive method, i.e. the air gap at maximum current is smaller than at rest. This method of tuning is cho-
sen mainly for large feed conveyors or products that are inclined to interlock. At very low frequencies the coil
yoke can lock-up when the current comes into phase with the vibratory movement., defined by the under fre-
quency limit.
2.3.3 Over-critical operation
For over-critical operation the drive frequency fais greater than the resonant frequency fres. When the damp-
ing increases the amplitude increases. Likewise, interlocking products tend to cause a reduction of the
feeders resonant frequency. In this operating method the power and vibratory movement are phase op-
posed, which dictate the use of a large reaction base and a higher current draw. In practice this method of
tuning is used in automation engineering where a large reaction base can be used, in most instances for
good engineering reasons, and the resonance curve is very flat because of high damping. The forced
stability achieved by high damping must, however, be traded against a high power usage.
3.0 Operating methods for vibratory feeders
3.1 Unregulated drive control
For unregulated control (output voltage control) the feeder must be tuned to operate away from resonant
frequency, by a specific amount. This difference determines the stability of a feeder, when it is subjected to
load changes, caused by the product. Depending on the feed system, the difference between the tuned fre-
quency and the resonant frequency is approximately ± 3Hz. When controllers with a fixed frequency are
used (e.g. thyristor or triac), the correct frequency is set by changing the spring pack and/or fitting compen-
sation weights. By using controllers that have a variable frequency output (frequency inverters), the electrical
drive frequency can be easily set to match the mechanical frequency, thus removing the need for time con-
suming mechanical tuning.
4
fres > fafres < fa
fres
fa
S [mm]
f [Hz]
a
b
c
d

3.2 Regulated drive control
It is possible to operate a vibratory feeder at resonance if a frequency inverter is used for holding the feeder
at resonant frequency and the amplitude at a level determined by a selected set-point. To achieve this, the
vibratory movement has to be measured and fed back to the frequency controller. Normally a sensor is fitted
to the vibrating part of the feeder to obtain this measurement. The signal generated is used not only to hold
the feeder at resonant frequency but also to maintain constant vibration amplitude by varying the output volt-
age. The feeder is always running with the greatest effectiveness when operating in this manner.
For more information refer to section 9.0 Guidance on using regulation control with frequency inverters.
4.0 REOVIB – Symbols
The following icons are used to denote unit functions
Straight line vibratory feeder
Vibratory feeder with a spiral track
Motor driven pre-feeder
Vibratory pre-feeder
Belt pre-feeder
Track control (product line)
Sensor for level control
Solenoid valve, e.g. for air blast
Control input START / STOP
Control output ON / OFF
5
0
I
0
I
Linear feeder
Bowl feeder
Elevator
Track
Sensor
Sensor
Position
Solenoid
Enable input
On / Off
Status output
On / Off
Hopper feeder
M
Band feeder

5.0 REOVIB – Terms
Through the course of time, various terms that sometimes seems different but is really the same, relating to
equipment, functions and characteristics, have evolved. These have been compiled, below, together with
explanations. In instances where there are several terms relating to a theme, the most widely used expres-
sion is underlined.
Bowl feeder
Feed equipment fitted with a round bowl that has a spiral track inside;
components move upwards and outwards along the track and tooling is
fitted sort the components so that they leave the feeder correctly orientated.
Linear feeder
Track feeder/ In-Line
feeder
Feed equipment for conveying orientated components in a straight line
Pre-feeder
Bunker / Feeder
hopper
Large vibratory feeders (bulk storage), feed conveyors or slatted belt ele-
vators; used for topping-up bowl feeders, over a long period, without the
need for manual intervention.
Component
Product, Material
The material or work-piece that is fed by the vibratory feeder
Vibrating frequency
The mechanical frequency at which the feeder vibrates.
In the case of thyristor or triac controllers this is completely dependent on
the mains supply frequency. When both half waves of the mains cycle are
used this gives a frequency that is twice that of the mains supply. When a
half-wave only is used this provides a frequency the same as that of the
mains supply.
A frequency inverter can provide a frequency that is independent of the
mains supply frequency.
Vibrating speed
Refers to the derivative of deflection against time
Amplitude
Deflection
Deflection of the feeder [mm] relative to the static air-gap between the coil
and armature; normally expressed as the entire backward/forward (±)
movement.
Resonant frequency
A particular frequency at which a feeder vibrates with the minimum power
requirement. In theory resonance is defined as the frequency that gives in-
finite amplitude.
Off-resonance condi-
tion
A difference between the operating frequency and the resonant frequency
of a vibratory feeder
Over-critical opera-
tion
Running a feeder at a frequency that is higher than resonant frequency; the
amplitude becomes smaller as loading or damping increases.
Under-critical damp-
ing
Running a feeder at a frequency that is lower than resonant frequency; the
amplitude is not affected by product loading.
Air-gap
Static air gap
The space between the coil and armature when a feeder is at rest
Feeder power
Feeder speed /
Feeder throughput
A measurement of the amount of components fed over a time period
Full-wave control
6000 vibs / min
100 Hz operation
Both mains, sine wave, half-cycles are controlled. The vibrating frequency
is twice the mains frequency.
6000 vibrations / min at 50Hz mains frequency
7200 vibrations / min at 60 Hz mains frequency
6

Half-wave control
3000 vibs / min
50 Hz operation
Only one half of the mains sine wave is controlled. The vibrating frequency
is the same as the mains frequency.
3000 vibrations/ min at 50 Hz mains frequency
3600 vibrations/ min at 60 Hz mains frequency
Soft start
To prevent a sudden switch-on to full feeder throughput; a ramp-up time is
used instead.
Purpose: To reduce the likelihood of coil hammering and components being
thrown off the feed track
Soft stop
The feeder is ramped down when the feeder is switched off by using the
enable input or track control.
Purpose: To reduce product storage changes
Umax / Umin
A facility to adjust the maximum and minimum output voltage levels of the
control equipment; the set-point range can then be varied between these
limits.
Purpose: For adapting different feeders to work with a controller
Track control
A component sensor is used, in conjunction with the controller, to maintain
a semi-constant level (queue) of product around a fixed point (sensor posi-
tion
Purpose: To reduce the unnecessary running time of feed equipment and
deterioration of product finish
Component high/low
level control
Control of component storage, between two track sensors
Purpose: To reduce the unnecessary running time of feed equipment and
deterioration of product
ton / toff
On/off switching time-delays
Purpose: To adjust a feeders response to track sensor signals
Pre-feeder control
Replenishment of product i response to a level control sensor,e.g. fitted in a
bowl feeder. When the depth of components drops below set a certain
level, the pre-feeder switches on and “tops-up” the feed system.
Coarse/fine control
Operation with two feeder speeds:fast and slow
Pulsed operation
Feeder runs with a pulsing, on/off action,e.g. to separate components
Accelerometer or am-
plitude sensor
A sensor to control the actual amplitude of a vibratory feeder
Can be used either for monitoring or as a feedback transducer for amplitude
regulation.
Mill controller
Used with small capacity grinding mills, to ensure that a mill is fed with the
optimum throughput of material. The feeder is regulated in response to the
loading of the mill. The motor current is used to monitor to mill loading.
Motor current increases as a greater amount of material is fed and so the
feeder throughput is reduced. When the motor current drops the feeder
throughput is increased.
Material sensor
Component sensor
A sensor that determines if components are present or not at a particular
point
This sensor can be a light barrier, initiator or a switch.
PNP / NPN output
Depending on its construction, a sensor can give out a positive signal e.g.
+24V, or in the case of an open collector provides a ground return path.
When a positive signal is provided this is referred to as a PNP output. When
the output is switched to earth this is referred to as an NPN output.
Active/passive
photo-electric sensor
Active photoelectric sensors have an integrated switch amplifier and give a
definite output signal that is either PNP or NPN.
For passive photoelectric sensors there must be provision in the control unit
for a photo-receiver to be used.
Namur sensor
A sensor that reacts to the proximity of metallic materials with a resistance
change
2 wire system
7

6.0 Functions of control units
6.1 Enable input or Stop/Start input
An input for interlocking with a supervisory systemm e.g. PLC or several controllers together, with a specific
relationship, e.g. paddle-switch regulation of a pre-feeder from a bowl feeder (see status output).
Inputs are usually configured for use with contacts or a 24 VDC signal. The controller runs when the contacts
are closed or 24 VDC is applied.
6.2 Status output
A contact or 24 VDC output signal to indicate if a feeder is on or off. The signal can be used to regulate
preceding or subsequent controllers, e.g. pre-feeder.
6.3 Soft start
When a feeder is turned on, the sudden thrust can cause components to be displaced or in extreme cases it
can cause the coil to hammer. To prevent this happenings the output voltage can be gradually ramped up.
The ramp up time is normally adjustable. This protects the feeder by providing a “soft start“.
6.4 Soft stop
To reduce the disturbance of components or material (in precision applications) a feeder can be slowly
ramped down to a stop. The ramp time is normally adjustable.
6.5 Coarse/fine control
To reduce overfilling when feeding material to a weighing machine, e.g. packing machines, a feeder can be
fun slower, shortly before reaching the target weight. Additional contacts are provided in a weigher for this
purpose. These contacts switch the controller to a second set-point level, which reduces the feeder through-
put. Upon reaching the target weight, the feeder switches off completely. This operating mode can be
selected in REOVIB digital controllers, as an alternative to using track control. The second set-point for “fine
feed“ is adjusted through the control panel. The sensor socket is used for the input signal.
6.6 Air valve output
Sometimes it is necessary, with troublesome components, to provide an air blast that will transfer product
from one feeder to another (e.g. from a bowl to a linear feeder). In such instances the air is only required
whilst a feeder is running. This output is configured so that the valve switches on one second before the
feeder starts and switches off four seconds after it stops.
6.7 Pulsed operation
A pulsed component flow is required for some applications, e.g. components that tangle or nest.
In digital controllers there is a function available and this has independently adjustable On/Off time settings.
See example below:-
8
1 s
4 s
Valvel
Feeder
1 s
Feeder
1,5 s
On
Off