WEST PAM-198-P Guide

Technical Documentation
PAM-198-P
Power amplifier for directional valves with feedback position control

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CONTENTS
1General Information......................................................................................................................................................4
1.1 Order Number.......................................................................................................................................................4
1.2 Scope of supply....................................................................................................................................................4
1.3 Accessories..........................................................................................................................................................4
1.4 Symbols used.......................................................................................................................................................5
1.5 Legal notice..........................................................................................................................................................5
1.6 Safety instructions................................................................................................................................................6
2Characteristics..............................................................................................................................................................7
2.1 Device description................................................................................................................................................8
3Use and application......................................................................................................................................................9
3.1 Installation instruction...........................................................................................................................................9
3.2 Typical system structure.....................................................................................................................................10
3.3 Method of operation............................................................................................................................................11
3.4 Commissioning...................................................................................................................................................12
4Function modes and technical description.................................................................................................................. 13
4.1 Input and output signals .....................................................................................................................................13
4.2 LED Indications ..................................................................................................................................................13
4.3 Circuit diagram ...................................................................................................................................................14
4.4 Typical wiring......................................................................................................................................................15
4.5 Input connection (examples)...............................................................................................................................15
4.6 Technical data....................................................................................................................................................16
5Parameter................................................................................................................................................................... 17
5.1 Parameter list .....................................................................................................................................................17
5.2 Basic parameters................................................................................................................................................19
5.2.1 LG (Changing the language for the help texts) ..........................................................................................19
5.2.2 MODE (Selecting visible parameter group)................................................................................................19
5.2.3 CTRLMODE (activation spool positioning control).....................................................................................19
5.2.4 CCMODE (Activation of the characteristic linearization)............................................................................20
5.2.5 SENS (Failure monitoring).........................................................................................................................20
5.3 Input signal adaption ..........................................................................................................................................21
5.3.1 AIN (Analogue input scaling) .....................................................................................................................21
5.3.2 SIGNAL:U (Type and polarity of the control signal) ...................................................................................22
5.3.3 VA:OFFSET (Zero point setting)................................................................................................................22
5.3.4 VA:MIN (Minimum control).........................................................................................................................23
5.3.5 VA:MAX (Maximum control).......................................................................................................................23
5.3.6 VA:TRIGGER (Response threshold for the MIN parameter)......................................................................23
5.4 Signal processing...............................................................................................................................................24
5.4.1 RA (Ramp function) ...................................................................................................................................24
5.4.2 CC (Characteristics linearization) ..............................................................................................................25
5.4.3 MIN (Overlap compensation).....................................................................................................................26
5.4.4 MAX (Output scaling).................................................................................................................................26
5.4.5 TRIGGER (Threshold value of MIN function).............................................................................................26
5.5 Parameters of the closed loop controller ............................................................................................................27
5.5.1 PID controller.............................................................................................................................................27
5.5.2 Integrator control........................................................................................................................................28
5.6 Parameters of the power stage...........................................................................................................................29
5.6.1 CURRENT (Nominal solenoid current) ......................................................................................................29
5.6.2 DAMPL (Dither amplitude).........................................................................................................................29
5.6.3 DFREQ (Dither frequency).........................................................................................................................29
5.6.4 PWM (PWM frequency).............................................................................................................................29

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5.6.5 ACC (Auto adaptation of the closed loop current controller)......................................................................30
5.6.6 PPWM (Solenoid current controller P gain)................................................................................................30
5.6.7 IPWM (Solenoid current controller I gain) ..................................................................................................30
5.7 Process data (Monitoring)...................................................................................................................................31
6Appendix.....................................................................................................................................................................31
6.1 Failure monitoring...............................................................................................................................................31
6.2 Troubleshooting..................................................................................................................................................32
7Notes..........................................................................................................................................................................33

Page 4 of 33 PAM-198-P 05.06.2020
1 General Information
1.1 Order Number
PAM-198-P - power amplifier for directional valves with feedback position control
1.2 Scope of supply
The scope of supply includes the module plus the terminal blocks which are a part of the housing.
The Profibus plug, interface cables and further parts which may be required should be ordered separately.
This documentation can be downloaded as a PDF file from www.w-e-st.de.
1.3 Accessories
WPC-300 - Start-Up-Tool (downloadable from our homepage –products/software)
Any standard cable with USB-A and USB-B connector can be used as the programming cable.

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1.4 Symbols used
General information
Safety-related information
1.5 Legal notice
W.E.St. Elektronik GmbH
Gewerbering 31
D-41372 Niederkrüchten
Tel.: [phone]
Fax.: [phone]
Homepage: www.w-e-st.de
EMAIL: [e-mail]
Date: 05.06.2020
The data and characteristics described herein serve only to describe the product. The user is required to
evaluate this data and to check suitability for the particular application. General suitability cannot be inferred
from this document. We reserve the right to make technical modifications due to further development of the
product described in this manual. The technical information and dimensions are non-binding. No claims may
be made based on them.
This document is protected by copyright.

Page 6 of 33 PAM-198-P 05.06.2020
1.6 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 (WPC-300 for the start-up software) 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 protec-
tion) 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 as-
sembly. 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 in-
struction 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.
CAUTION!
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.
When not in use the module must be protected from the effects of the weather, contamina-
tion and mechanical damage.
The module may not be used in an explosive environment.
To ensure adequate cooling the ventilation slots must not be covered.
The device must be disposed of in accordance with national statutory provisions.

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2 Characteristics
This module is used for the control of the spool position of directional valves with electrical feedback. Various
adjustable parameters allow for an optimized adaptation to the respective valve. The integrated power ampli-
fier with a short cycle time of 0,125 ms for the current loop is an inexpensive and space-saving solution. The
closed loop of the application works with a sample time of 1 ms.
Command value and feedback value are read in via free scalable analog inputs (voltage signals in the range
of 0… 10V or +/-10V respectively current signals in the range of 4… 20mA). The output current is closed loop
controlled and therefore independent from the power supply and the solenoid resistance. The output stage is
monitored for cable breakdown, is short circuit proof and disables the power stage in case of an error.
RAMP, MIN and MAX, the DITHER (frequency and amplitude) and the PWM frequency are programmable.
In addition, the valve characteristics can be linearized via 10 XY-points.
Features
Control of directional valves with spool position feedback
Compact housing
Digital reproducible adjustments
Free scaling of the analogue inputs
PID controller with feed forward function
Controlling valves with one or two solenoids
Bipolar controlling via differential input
Characteristics linearization via 10 XY-points per direction
Free parameterization of RAMPS, MIN und MAX, output current, DITHER (frequency, amplitude)
Nominal output current range up to 2.6 A
Simple and application orientated parameter settings via WPC-software
Failure monitoring and extended function check

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2.1 Device description
V:
ID:
Add.:Date:
Made in Germany
W.E.ST.
Ready
1 2 3 4
5 6 7 8
910 11 12
14 15 1613
D-41372 Niederkrüchten
Homepage: http://www.w-e-st.de
W.E.ST. Elektronik
13 14 15
910 11 12
16
A B
Klemmblöcke (steckbar)
Terminals (removable)
LEDs
USB
interface
Typenschild undAnschlussbelegung
Type plate and terminal pin assignment
23,0000 mm99,0000 mm
114,0000 mm

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3 Use and application
3.1 Installation instruction
This module is designed for installation in a shielded EMC housing (control cabinet). All cables which
lead outside must be screened; complete screening is required. It is also a requirement that no strong
electro-magnetic interference sources are installed nearby when using our open and closed loop con-
trol modules.
Typical installation location: 24V control signal area (close to PLC)
The devices must be arranged in the control cabinet so that the power section and the signal section
are separate from each other.
Experience shows that the installation space close to the PLC (24 V area) is most suitable. All digital
and analogue inputs and outputs are fitted with filters and surge protection in the device.
The module 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 wir-
ing scheme is recommended. The following points must be observed when wiring:
The signal cables must be laid separately from power cables.
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 module as possi-
ble. 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 –the manufacturer should be
consulted if necessary.
A low-resistance connection between PE and the mounting rail should be provided. Transient interfer-
ence is transmitted from the module directly to the mounting rail and from there to the local earth.
Power should be supplied by a regulated power supply unit (typically a PELV system complying with
IEC364-4-4, secure low voltage). The low internal resistance of regulated power supplies gives better
interference voltage dissipation, which improves the signal quality of high-resolution sensors in partic-
ular. 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 Typical system structure
This minimum example system contains of following components:
(*1) Proportional valve
(*2) Spool position sensor
(*3) Control module PAM-198-P
(*4) Interface to the PLC