Bucher Hydraulics EVS-AU1-2500 Series User manual

Reference: 400-B-900009-EN-00
Issue: 10.2021 1/24
Operating Instruction
Universal power amplifier for proportional valves
Series EVS-AU1-2500… & EVS-AI1-2500…

Reference: 400-B-900009-EN-00
Issue: 10.2021 2/24
Published by
Bucher Hydraulics AG Frutigen
Schwandistrasse 25
CH-3714 Frutigen
Phone [phone]
Email [email protected]
Internet www.bucherhydraulics.com
© 2021 by Bucher Hydraulics AG Frutigen, CH-3714 Frutigen
All rights reserved. This documentation, in whole and/or in part, is protected by copyright. It may not be reproduced,
nor may it be stored, processed, replicated or distributed by electronic means, without written permission from Bucher
Hydraulics.
Data is provided for the purpose of product description only, and must not be construed as warranted characteristics
in the legal sense. No assertion regarding either a particular property or the fitness for a particular intended purpose
can be derived or deduced from this information. The information does not relieve users from the duty of conducting
their own evaluations and tests. Because the products are subject to continual improvement, we reserve the right to
amend the product specifications contained in this catalogue. The original language and legal terminology of all Bucher
Hydraulics documentation is exclusively German. Bucher Hydraulics cannot be held liable for any possible errors in
translation.

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CONTENTS
1General Information ............................................................................................................ 5
1.1 Order number ..................................................................................................................5
1.2 Alternative products.........................................................................................................5
1.3 Scope of supply...............................................................................................................5
1.4 Accessories .....................................................................................................................5
1.5 Safety instructions ...........................................................................................................6
2Characteristics .................................................................................................................... 7
2.1 Features ..........................................................................................................................7
2.2 Device description ...........................................................................................................8
3Use and application ............................................................................................................ 9
3.1 Installation instructions ....................................................................................................9
3.2 Commissioning..............................................................................................................10
4Technical description ....................................................................................................... 11
4.1 Input and output signals ................................................................................................11
4.2 LED definitions ..............................................................................................................11
4.3 Block diagram................................................................................................................12
4.4 Typical wiring.................................................................................................................12
4.5 Technical data ...............................................................................................................13
5Manual parametrization .................................................................................................... 14
5.1 Parameter overview.......................................................................................................14
5.2 Procedural method ........................................................................................................15
6Parameters......................................................................................................................... 15
6.1 Parameter list ................................................................................................................15
7Parameter description ...................................................................................................... 16
7.1 LG (Changing language) ...............................................................................................16
7.2 MODE (Switching between parameter groups) .............................................................16
7.3 AIN ((Analogue input scaling)........................................................................................16
7.4 LIM (Signal monitoring) .................................................................................................18
7.5 R (Command signal ramp time).....................................................................................18
7.6 MIN (Overlap compensation) / MAX (output scaling) / TRIGGER (Threshold value of
MIN)...............................................................................................................................19
7.7 POL (Output polarity).....................................................................................................19
7.8 CURRENT (Rated current range)..................................................................................20
7.9 DAMPL / DFREQ (Ditheramplitude and Dither frequency)............................................20
7.10 PWM (PWM Frequenz) .................................................................................................20
7.11 PPWM / IPWM (Solenoid current controller P gain and I-gain) .....................................21
7.12 PROCESS DATA (Monitoring) ......................................................................................21

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8Appendix............................................................................................................................ 22
8.1 Failure monitoring..........................................................................................................22
8.2 Troubleshooting.............................................................................................................22
9History................................................................................................................................ 24

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1 General Information
1.1 Order number
EVS-AU1-2500-1-30D-A1 - Universal power amplifier with 0... 10V input for
proportional valves
1.2 Alternative products
EVS-AI1-2500-1-30D-A1 - Universal power amplifier with 4...20mA input for
proportional valves
1.3 Scope of supply
The scope of supply includes the module. Cables, adapters and further parts which may be
required should be ordered separately. This documentation can be downloaded as a PDF file
from www.bucherhydraulics.com.
1.4 Accessories
PS1 - GUI for parametrization and monitoring of the power
amplifier (free download from www.bucherhydraulics.com)
EKL-USB-LIN-1-30D-A1 - Programming adapter with USB interface

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1.5 Safety instructions
Please read this document and the safety instructions carefully. This document will help to
define the product area of application and to put it into operation. Additional documents and
knowledge of the application should be taken into account or be available. General regulations
and laws (depending on the country: e.g. accident prevention and environmental protection)
must be complied with.
These modules are designed for hydraulic applications in open or closed
loop control circuits. Uncontrolled movements can be caused by device
defects (in the hydraulic module or the components), application errors
and electrical faults. Work on the drive or the electronics must only be
carried out whilst the equipment is switched off and not under pressure.
This handbook describes the functions and the electrical connections for
this electronic assembly. All technical documents which pertain to the
system must be complied with when commissioning.
This device may only be connected and put into operation by trained
specialist staff. The instruction manual must be read with care. The
installation instructions and the commissioning instructions must be
followed. Guarantee and liability claims are invalid if the instructions are
not complied with and/or in case of incorrect installation or inappropriate
use.
All electronic modules are manufactured to a high quality. Malfunctions
due to the failure of components cannot, however, be excluded. Despite
extensive testing the same also applies for the software. If these devices
are deployed in safety-relevant applications, suitable external measures
must be taken to guarantee the necessary safety. The same applies for
faults which affect safety. No liability can be assumed for possible
damage.
Further instructions
•The module may only be operated in compliance with the national
EMC regulations. It is the user’s responsibility to adhere to these
regulations. The device is only intended for use in the commercial
sector.
•The module may not be used in an explosive environment.
•The device must be disposed of in accordance with national
statutory provisions.

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2 Characteristics
This amplifier plug is used to control proportional valves with one solenoid. The compact
solution will be mounted directly on the solenoid.
A typical input signal of 0…10 V (optional 4…20mA) can be used. The output current is closed
loop controlled and therefore independent from the supply voltage and a varying solenoid
resistance.
The parametrization can be done via the PC interface and the EKL-USB-LIN-1-30D-A1
programming adapter or internally via the UP and DOWN buttons.
2.1 Features
•Power amplifier for proportional valves located in a DIN EN 175 301-803-A plug housing
•Digitally reproducible adjustments
•Free scaling of the input signal
•Also usable as Soft-Switch-amplifier (soft switch-on and switch-off)
•M12 connector
•Programmable via USB/LIN bus
•Free parameterization of Ramps, Minimum- and Maximum current, Dither (frequency,
amplitude) and PWM frequency
•Parameter settings via integrated buttons and a selector switch (reduced functionally
against the USB / LINbus)
•Nominal output current range: 0.5… 2.5 A

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2.2 Device description

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3 Use and application
3.1 Installation instructions
•All cables which lead outside must be shielded; a complete shielding is required. It is
also a requirement that no strong electro-magnetic interference sources are installed
nearby when using our control and regulation modules.
•The equipment should be installed and wired in accordance with the documentation
bearing in mind EMC principles. If other consumers are operated with the same power
supply, a star- connected ground wiring scheme is recommended. The following points
must be observed when wiring:
•Analogue signal cables must be screened.
•All other cables must be screened if there are powerful interference sources
(frequency converters, power contactors) and cable lengths > 3m. Inexpensive
SMD ferrites can be used with high-frequency radiation.
•The screening should be connected to PE (PE terminal) as close to the
equipment as possible. The local requirements for screening must be taken
into account in all cases. The screening should be connected to at both ends.
Equipotential bonding must be provided where there are differences between
the connected electrical components.
•With longer lengths of cable (>10 m) the diameters and screening measures
should be checked by specialists (e.g. for possible interference, noise sources
and voltage drop). Particular care is required with cables of over 40 m in
length
•A low-impedance connection between PE and valve must be provided. Transient
interference voltages are conducted from the device directly to the valve and thus to
local grounding.
•Power should be supplied by a regulated power supply unit (typically a PELV system
complying with IEC364-4-4, secure low voltage) or by a battery. The low internal
resistance of regulated power supplies gives better interference voltage dissipation,
which improves the signal quality of high-resolution sensors in particular. Switched
inductances (relays and valve coils connected to the same power supply) must always
be provided with appropriate overvoltage protection directly at the coil.

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3.2 Commissioning
Step Task
Installation Install the device in accordance with the circuit diagram. Ensure it
is wired correctly and that the signals are well shielded.
Switching on for the first
time
Ensure that no unwanted movement is possible in the drive (e. g.
switch off the hydraulics). Connect an amperemeter and check the
current consumed by the device. If it is higher than specified, there
is an error in the wiring. Switch the device off immediately and
check the wiring.
Setting up communication
Once the power input is correct the PC (notebook) should be
connected via the USB interface and the programming adapter
EKL-USB-LIN-1-30D-A1. Please see PS1 software documentation
for how to set up communication.
The communication works in a “half duplex” process. Further
commissioning and diagnosis are supported by the operating
software. Alternatively, the set-up can be done by the internal
parameter selector and the “up” and “down” buttons.
Pre-parameterization
Parameterize now (with the help of the system redundancy and the
connection diagram) the following parameters:
The “analog input”, the output “current” and the typical valve
parameter “dither” and “min/max”.
Pre-parameterization is necessary to minimize the risk of an
unintentional movement.
Control signal
Check the control signal (output signal). The control signal
(solenoid current) lies in the range of 0... 2.5 A. In the current state
it should show around 0 A.
The valve current can also be monitored in the PS1 software.
Switching on the
hydraulics
The hydraulics can now be switched on. The module is not yet
generating a signal. Drives should be at a standstill or drift slightly
(leave its position at a slow speed).
Activating command
signal
The output current to the valve will follow the input signal
proportionally.
The power stage is always active when power supply exists. Drives
can now leave their position and move to an end position at full
speed. Take safety measures to prevent personal injury and
damage.
Optimize settings Now optimize the remaining parameters according to your
application and your requirements.

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4 Technical description
4.1 Input and output signals
4.2 LED definitions
Connection
Supply
PIN 1 Power supply (see technical data)
PIN 3 0 V (GND) Power supply (ground).
Connection
Analogue signals
PIN 2 Command signal input +, signal range 0… 10 V, scalable
PIN 4 Command signal input -, signal range 0… 10 V, scalable
Connection
Communication
PIN 5
LIN-bus communication port
Via EKL-USB-LIN-1-30D-A1 programming adapter the plug can be read out
and parameterized.
LEDs
Description of the LED function
YELLOW
(THT)
READY display
OFF: No power supply
ON: System is ready for operation
Flashing: Error discovered
YELLOW
(SMD)
Operational mode
Off: Normal operation
Flashing sequences at rotary switch position 0...6: Manual parameter
setting mode is active
At rotary switch position 8: from indication "Off" via increasing flashing
duration to continuous light, the "output current" is displayed.
At rotary switch position 9: from indication "Off" via increasing flashing
duration to continuous light, the "setpoint" is displayed

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4.3 Block diagram
4.4 Typical wiring

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4.5 Technical data
Supply voltage (Ub)
Current consumption (w/o solenoid)
External fuse
[VDC]
[mA]
[A]
12… 30 (incl. ripple)
< 50
3 medium time lag
Analog inputs:
Voltage
Input resistance
Signal resolution
Current
Burden
Signal resolution
[V]
[kOhm]
[%]
[mA]
[Ohm]
[%]
Unipolar / differential
0…10
> 90
0.026
4…20
240
0.055
PWM output
Max. output current
Frequency
[A]
[Hz]
Wire break and short circuit monitored
2.5
61...2604 selectable in defined steps
Sample times
Solenoid current control
Signal processing
[µs]
[ms]
167
1
Serial Interface
Transmission rate
-
[kBaud]
LIN-Bus
19.2
Housing acc. DIN EN 175301-803-A
Material
Color
Flammability class
-
-
-
-
3-pole 2 P+E
PA 6.6 polyamide
black
V0 (UL94)
Weight [g] 80
Protection class -
IP65 with gasket
(with appropriate mating connector and
proper fitting and sealing)
Temperature range
Storage temperature
Humidity
[°C]
[°C]
[%]
-20… +65
-20 …+70
<95 (not condensing)
Connections M12, 5pole (DESINA standard)
EMC EN 61000-6-2: 8/2005
EN 61000-6-4: 6/2007 + A1:2011

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5 Manual parametrization
5.1 Parameter overview
The manual adjustment is comparable with the adjustment via potentiometer. Not all parameters
of the power plug are available in this mode. For full functionality, the use of the PC interface is
necessary.
Switchposition Parameter Range Remarks
0 DEFAULT -
Released only by pressing the button "up"
and "down" simultaneously.
Response: A short and fast flashing of the
LED.
1 CURRENT 0 | 1 0 = low current range; press „down“
1 = high current range; press „up“
2 MIN 0…60% Deadband compensation in relation to the
current range
3 MAX 30…100% Reduction in the maximum current in
relation to the current range
4
R:UP
50ms…5sec
Ramp time up
5
R:DOWN
50ms…5sec
Ramp time down
6
PWM
61…2604 Hz
PWM output frequency
7
-
No function
8 - Current monitoring, no parameter input, see
LED definitions.
9 - Setpoint monitoring, no parameter input,
see LED definitions.

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5.2 Procedural method
Task Parameter
1 Press a button or turn the selector switch, which activates the manual adjustment
mode. The parameter-LED flashes.
2
Select the desired parameter (1… 6) by the selector switch.
3
The parameter LED indicates - by flashing - the parameter mode.
a. At the lower boundary the LED lights only briefly
b. At the upper boundary the LED lights almost continuously
4
Press the UP or DOWN button.
a. A short activation of one of the buttons will change the
parameter by a value of app. 1%.
b. A continual activation of one of the buttons will change the
parameter continually (up to the point where the upper or
lower boundary is reached).
5 The parameters are stored automatically (app. 1 second after the last parameter
adjustment). The manual adjustment will be finished after 60 seconds.
6 Parameters
6.1 Parameter list
Command Default Unit Description
LG EN - Changing language help texts
MODE STD - Parameter mode (standard or expert)
AIN:W
a: 1000
b: 1000
c: 0
X: V
-
-
0.01 %
-
Free scaling of the analogue input signal
LIM 0 0.01% Signal monitoring function (e.g. joystick error)
R:UP
R:DOWN
100
100
ms
ms Command signal ramp times
MIN 0 0.01 % Compensation of the dead band
MAX 10000 0.01 % Scaling of the max. output signal
TRIGGER 200 0.01 % Trigger point for activating the MIN value.
POL + - Output polarity
CURRENT 0 - Current output range
DAMPL 0 0.01 % Dither amplitudes. Related to the nominal output

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Command Default Unit Description
current.
DFREQ 120 Hz Dither frequency
PWM 488 Hz PWM frequency
PPWM
IPWM
1
40
-
- Parameters for the closed loop current controllers
7 Parameter description
7.1 LG (Changing language)
Command Parameter Unit Group
LG x x= DE | EN - STD
Either German or English can be selected for the help texts in the PS1 software.
After changing the language settings, the parameter list has to be updated by
pressing the speed button “ID” in the PS1.
7.2 MODE (Switching between parameter groups)
Command Parameter Unit Group
MODE x x= STD | EXP - STD
This command changes the parameter mode. Various commands (defined via STD/EXP) are
blanked out in standard mode. The several commands in expert mode have more significant
influence on the system performance. Therefore they should be changed with care.
7.3 AIN ((Analogue input scaling)
Command Parameter Unit Group
AIN:W
a
b
c
x
a= -10000… 10000
b= -10000… 10000
c= -10000… 10000
x= V | C
-
-
0.01 %
-
STD

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This command offers an individual scalable input. The following linear equation is used for the
scaling.
 =
∗( − )
The “C” value is the offset (e.g. to compensate the 4 mA in case of a 4… 20 mA input signal).
The variables A and B are defining the gain factor with which the signal range is scaled up to
100 % (e.g. 1.25 if using 4… 20mA input signal, defined in default current settings by A = 1250
and B = 1000). The internal shunt for the current measuring is activated with switching the X
value.
The gain factor is calculated by setting the usable range (A) in relation to the real used range
(B) of the input signal. Usable are 0… 20mA, means (A) has the value 20. Really used are 4…
20mA, means (B) has a value of 16 (20-4). Not used are 0… 4mA. In a range of 20mA this is an
offset of 20%, means a value of 2000 for (C). Finally (X) has to be set to C choosing current
signal.
In this case AIN command would look like this:
AIN:I 20 16 2000 C or AIN:I 1250 1000 2000 C.
FUNCTION = 195 Input signal Description
AIN:X 1000 1000 0 V 0… 10 V Range 0...100%
AIN:X 10 8 1000 V
OR
AIN:X 1250 1000 1000 V
1… 9 V
Range: 0… 100 %
1 V = 1000 used for the offset and
gained by 10 / 8 (10 V divided by 8 V
(9 V -1 V))
AIN:X 10 4 500 V
OR
AIN:X 2500 1000 500 V
0.5... 4.5 V
Range: 0… 100 %
0,5 V = 500 used for the offset and
gained by 10 / 4 (10 V divided by 4 V
(4.5 V -0.5 V))
AIN:X 20 16 2000 C
OR
AIN:X 2000 1600 2000 C
OR
AIN:X 1250 1000 2000 C
4… 20 mA
Range: 0… 100 %
The offset will be compensated on 20
% (4 mA) and the signal (16 mA = 20
mA – 4 mA) will be gained to 100 %
(20 mA).
Each of this parameterization for 4…
20 mA is setting the range to 0… 100
%.

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7.4 LIM (Signal monitoring)
Command Parameter Unit Group
LIM x x= 0… 2000 0.01 % EXP
The signal monitoring deactivates the output current if the input signal leaves the permitted
range after scaling. This function makes it possible to detect a short circuit or cable break of a
joystick or potentiometer.
Example: LIM 500 (5% lower/upper limitation)
If the input signal gets higher than 95 % or lower than 5%, it leaves the permitted range and the
outputs will switch off.
7.5 R (Command signal ramp time)
Command Parameter Unit Group
R:I x i= UP | DOWN
x= 50… 10000 ms STD
The ramp time is set separately for the rising (UP) and falling ramp (DOWN).
The ramp time is related to 100 % signal step.

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7.6 MIN (Overlap compensation) / MAX (output scaling) / TRIGGER (Threshold value
of MIN)
Command Parameter Unit Group
MIN x
MAX x
TRIGGER x
x= 0… 6000
x= 2000… 10000
x= 0… 3000
0.01 %
0.01 %
0.01 %
STD
The output signal is adapted to the valve by these commands. With the MAX value the output
signal (the maximum valve current) will be defined. With the MIN value the overlap (dead band
of the valve) will be compensated.
Via the TRIGGER command the activation point of the MIN function is set and so a non-
sensitive range around the zero-point can be specified. This threshold is necessary, in order to
avoid unrequested activations caused by small variations of the input signal.
If the MIN value is set too high, it influences the minimal velocity, which
cannot be adjusted any longer.
7.7 POL (Output polarity)
Command Parameter Unit Group
POL x x= + | - - EXP
This command allows a switch over of the output signal direction (after the MIN-MAX function).
Example: POL:A + Input signal 0… 100 %, nominal output current 0… 100 %.
POL:A - Input signal 0… 100 % nominal output current 100… 0 %.

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7.8 CURRENT (Rated current range)
Command Parameter Unit Group
CURRENT x i= 0 | 1 - STD
The nominal current range is set with this parameter. Dither and also MIN/MAX always refer to
the selected current range.
0 = 1.0 A range
1 = 2.5 A range
7.9 DAMPL / DFREQ (Ditheramplitude and Dither frequency)
Command Parameter Unit Group
DAMPL x
DFREQ x
x= 0… 3000
x= 60… 400
0.01 %
Hz EXP
The dither can be defined freely with this command. The DITHER is a superimposed signal to
reduce the hysteresis. This function is defined by the amplitude and frequency. The DITHER
frequency should not be confused with the PWM frequency.
Different amplitudes or frequencies may be required depending on the respective valve. The
dither amplitude is defined in % of the nominal current.
The PPWM and IPWM parameters influence the effect of the dither setting.
These parameters should not be changed again after the dither has been
optimized.
If the PWM frequency is less than 500 Hz, the dither amplitude should be set
to zero.
7.10PWM (PWM Frequenz)
Command Parameter Unit Group
PWM x x= 61… 2604 Hz EXP
This parameter is entered in Hz. The optimum frequency depends on the valve.
Due to the longer dead times at low PWM frequencies the stability of the
control circuit is reduced. When using low PWM frequencies the PPWM and