W.E.S.T. Elektronik PAM-195-P-S3 Guide
Technical Documentation
PAM-195-P-S3
Power amplifier for directional valves with integrated power limitation function
Page 2 of 35 PAM-195-P-S3 05.06.2020
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 Commissioning...................................................................................................................................................10
3.3 Range of applications.........................................................................................................................................11
3.3.1 Limitation of the output power....................................................................................................................11
3.3.2 Limitation of the input/common power .......................................................................................................11
4Function modes and technical description.................................................................................................................. 12
4.1 LED Indications ..................................................................................................................................................12
4.2 Typical system structure.....................................................................................................................................13
4.3 Method of operation............................................................................................................................................13
4.4 Input and output signals .....................................................................................................................................14
4.5 Circuit diagram ...................................................................................................................................................15
4.6 Typical wiring......................................................................................................................................................16
4.7 Input connection (examples)...............................................................................................................................17
4.8 Technical data....................................................................................................................................................18
5Parameter................................................................................................................................................................... 19
5.1 Parameter list .....................................................................................................................................................19
5.2 Basic parameters................................................................................................................................................21
5.2.1 LG (Changing the language for the help texts) ..........................................................................................21
5.2.2 MODE (Switching between parameter groups)..........................................................................................21
5.2.3 AINMODE (Mode of input scaling).............................................................................................................21
5.2.4 SENS (Failure monitoring).........................................................................................................................22
5.2.5 CCMODE (Activation of the characteristic linearization)............................................................................22
5.2.6 SOLENOIDS (One or two solenoids).........................................................................................................22
5.2.7 POL (Output polarity).................................................................................................................................23
5.3 Input signal adaption ..........................................................................................................................................23
5.3.1 SIGNAL (Switching the type of input signal)..............................................................................................23
5.3.2 AIN (Analogue input scaling) .....................................................................................................................24
5.3.3 SYS_RANGE (Rated pressure of the system)...........................................................................................25
5.3.4 N_RANGE:X (Nominal pressure of the sensor).........................................................................................25
5.3.5 OFFSET:X (Zero point setting of the sensor).............................................................................................25
5.3.6 RA (Ramp function) ...................................................................................................................................26
5.4 Power limitation function.....................................................................................................................................26
5.4.1 PL:V (Power limitation factor) ....................................................................................................................26
5.4.2 PL:T1 (Dynamic of the power limitation function).......................................................................................26
5.5 Output signal adaption........................................................................................................................................27
5.5.1 CC (Characteristics linearization) ..............................................................................................................27
5.5.2 MIN (Overlap compensation).....................................................................................................................28
5.5.3 MAX (Output scaling).................................................................................................................................28
5.5.4 TRIGGER (Threshold value of MIN function).............................................................................................28
5.6 Parameters of the power stage...........................................................................................................................29
Page 3 of 35 PAM-195-P-S3 05.06.2020
5.6.1 CURRENT (Nominal output current)..........................................................................................................29
5.6.2 DAMPL (Dither amplitude).........................................................................................................................29
5.6.3 DFREQ (Dither frequency).........................................................................................................................29
5.6.4 PWM (PWM frequency) .............................................................................................................................30
5.6.5 ACC (Auto adaptation of the closed loop current controller)......................................................................30
5.6.6 PPWM (Solenoid current controller P gain)................................................................................................31
5.6.7 IPWM (Solenoid current controller I gain) ..................................................................................................31
5.7 Process data (Monitoring)...................................................................................................................................31
6Appendix.....................................................................................................................................................................32
6.1 Failure monitoring...............................................................................................................................................32
6.2 Troubleshooting..................................................................................................................................................32
6.3 Differences to former product generations..........................................................................................................33
6.3.1 Baudrate of the serial Interface..................................................................................................................33
6.3.2 Output current adjustment / MIN_MAX / RCURR ......................................................................................33
6.4 Description of the command structure................................................................................................................34
7Notes..........................................................................................................................................................................35
Page 4 of 35 PAM-195-P-S3 05.06.2020
1 General Information
1.1 Order Number
PAM-195-P-S3 - power amplifier for directional valves with integrated power limitation function
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.
Page 5 of 35 PAM-195-P-S3 05.06.2020
1.4 Symbols used
General information
Safety-related information
1.5 Legal notice
W.E.St.
Elektronik GmbH
Gewerbering 31
D-41372 Niederkrüchten
Tel.: +49 (0)2163 577355-0
Fax.: +49 (0)2163 577355 -11
Home page: www.w-e-st.de
EMAIL: contact@w-e-st.de
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 35 PAM-195-P-S3 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.
Page 7 of 35 PAM-195-P-S3 05.06.2020
2 Characteristics
This module is used for the control of a directional valve with two solenoids or a pressure or throttle valve with
one solenoid. Various adjustable parameters allow for an optimized adaptation to the respective valve. The
integrated power amplifier with a short cycle time of 0,125 ms for the current loop is an inexpensive and
space-saving solution.
Additionally to the amplifier function a power limitation functionality via an analogue input was implemented.
Switching the direction was realized by a digital switching input. It is also possible to do it with an adapted
scaling of the command input. Within that a simple unipolar output of a plc can control this amplifier. Control-
ling it with a bipolar signal from -10 to 10V is possible, too.
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. For example: using pressure valves a
linear behavior between input signal and pressure can be reached.
Typical applications: Control of directional, throttle and pressure valves, which need a flexible adaptation of the
solenoid control. All typical proportional valves of the different manufactures (BOSCH, REXROTH, PARKER,
EATON ...) can be controlled.
Features
Control of directional, pressure or throttle valves
Compact housing
Digital reproducible adjustments
Free scaling of the analogue inputs
Power limitation functionality via analogue input
Unipolar controlling with direction switch
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: 0,5… 2,6 A
Simple and application orientated parameter settings via WPC-software
Failure monitoring and extended function check
Page 8 of 35 PAM-195-P-S3 05.06.2020
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
Page 9 of 35 PAM-195-P-S3 05.06.2020
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.
Page 10 of 35 PAM-195-P-S3 05.06.2020
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. The device must be installed in a protective
housing (control cabinet or similar).
Switching on for the first
time
Ensure that no unwanted movement is possible in the drive (e.g. switch off the
hydraulics). Connect an ammeter 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 imme-
diately and check the wiring.
Setting up communication
Once the power input is correct the PC (notebook) should be connected to the
serial interface. Please see the WPC-300 program documentation for how to set up
communication.
CAUTION! Compared to older modules the standard baudrate of the interface
was changed to 57600 Baud. Please set the WPC-300 to 57600 Baud or to the
automatic baudrate recognition as described under OPTIONS/SETTINGS, point
6.3.1.
ATTENTION! A USB driver has to be installed and properly configured.
See WPC-300 short guideline.
Further commissioning and diagnosis are supported by the operating software.
ATTENTION! The COMPORT (in WPC-300) has to be closed before the USB plug
is to be disconnected. Otherwise the WPC-300 is going to be instable.
Pre-parameterization
Now set up the following parameters (with reference to the system design and circuit
diagrams):
The nominal output CURRENT and the typical valve parameters such as DITHER
and MIN/MAX.
Pre-parameterization is necessary to minimize the risk of uncontrolled movements.
Control signal
Check the control signal with an amp meter. The control signal (the current of the
solenoid) is within the range of 0... 2, 6A. In the actual status it should show approxi-
mately 0 A.
ATTENTION! You can monitor the current of the solenoids also in the WPC-300 pro-
gram.
Switching on the hydrau-
lics
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) if it
is a proportional valve.
Activating ENABLE
CAUTION! The drive can now leave its position and move to an end position with full
speed or the pressure can reach maximum. Take safety measures to prevent per-
sonal injury and damage.
Page 11 of 35 PAM-195-P-S3 05.06.2020
3.3 Range of applications
The amplifier described in this document provides a power limitation functionality. This can be used in different
ways.
3.3.1 Limitation of the output power
Depending on the measured pressure in the application the volumetric flow will be reduced above a pro-
grammed threshold. This is a typical application which is the reason for displaying the feedback value also in
bar.
3.3.2 Limitation of the input/common power
In this kind of use several devices get a signal for the power consumption of the whole system as feedback.
So single valves can open without limitation. Even if the system reaches its borderline for overload, all valves
will be limited uniformly.
Page 12 of 35 PAM-195-P-S3 05.06.2020
4 Function modes and technical description
4.1 LED Indications
LEDs
Description of the LED function
GREEN + YELLOW
1. Chasing light (over all LEDs): The bootloader is active. No normal functions
are possible.
2. All LEDs flash shortly every 6 s: An internal data error was detected and cor-
rected automatically! The module still works regularly. To acknowledge the error
the module has to be cycle powered.
YELLOW + YELLOW
Both yellow LEDs flash oppositely every 1 s: The nonvolatile stored parameters
are inconsistent! To acknowledge the error the data have to be saved with the SAVE
command or the corresponding button in the WPC. If the function of the module has
changed via the FUNCTION parameter, all parameters are deleted purposely and set
to default values. In this case the LEDs indicate no error, but a desired state. To
acknowledge please save.
GREEN
Identical to the READY output.
OFF: No power supply or ENABLE is not activated
ON: System is ready for operation
Flashing: Error detected (e. g. valve solenoid or 4… 20 mA).
Not active when SENS = OFF.
YELLOW
LED in the middle position = Current to the solenoid; the intensity is proportional to
the actual output current.
LED in the right position = Power limitation; the LED indicates, whether the device
is in power limitation range or not.
Page 13 of 35 PAM-195-P-S3 05.06.2020
4.2 Typical system structure
This minimal system consists of the following components:
(*1) proportional valve
(*2) hydraulic cylinder
(*3) power amplifier PAM-195-P-S3
(*4) interface to PLC with analogue and digital signals
(*5) power input, from pressure sensor or pump
4.3 Method of operation
This power amplifier is controlled by an analogue signal (from the PLC, from a joystick or a potentiometer). An
ENABLE signal (typically 24V) activates the module and the READY output indicates this, if no internal or ex-
ternal error was detected.
The integrated standard functions will be configured via different parameters.
In case of a fault, the power output stage will be deactivated and the fault will be indicated through a deac-
tivated READY output and a flashing READY LED.
The output current is closed loop controlled whereby a high accuracy and a good dynamic will be obtained. All
custom proportional valves (up to 2,6A) may be controlled with this power amplifier.
This modified module is basically controlled by an unipolar command signal in the range of 0... 10V or 4...
20mA. A switching input is used for changing direction. By this way directional valves can be controlled via in-
expensive unipolar plc outputs. Special feature of this module is the power limitation function. For that an up-
per limit for each direction can be preset. Due to reducing the flow rate depending on the actual pressure this
limits will observed. Via this calculation for power limitation the output value (the flow) will be reduced:
INPUT means the measured signal for power limitation (e.g. the pressure) and PLV(parameter PL:V) the
power factor in % related to the maximum. The output signal will be limited down to the OUTPUTLIM value.
Page 14 of 35 PAM-195-P-S3 05.06.2020
4.4 Input and output signals
Connection
Supply
PIN 7
Power supply (see technical data)
PIN 8
0 V (GND) Power supply (ground).
Attention, PIN 8 and PIN 11 are connected internally. PIN 11 is used as the GND potential
for the command and feedback signals.
Connection
Reference voltages output
PIN 12
Reference output voltage (8 V).
Connection
PWM output
PIN 3 / 4
Current controlled PWM outputs for solenoid A.
PIN 1 / 2
Current controlled PWM outputs for solenoid B.
Connection
Analogue input signals
PIN 9 / 10
Command (input) signal (W), range -100…100 % or 0… 100 % corresponds with 0…10 V or
4…20 mA. Other signal ranges can be scaled.
PIN 14 / 13
Feedback input (actual pressure), range 0… 10 V or 4… 20 mA corresponds with 0… 100 %.
PIN 11
0 V reference for the signal inputs.
Connection
Digital inputs and outputs
PIN 15
Enable Input:
This digital input signal initializes the application.
The output and the READY signal will be activated.
By deactivating error signals are reset.
PIN 6
Direction input:
Switching direction (changing solenoids).
PIN 5
READY output:
ON: Module is ready, no errors are detected
OFF: ENABLE (PIN 15) is deactivated or an error is detected.
Page 15 of 35 PAM-195-P-S3 05.06.2020
4.5 Circuit diagram
+UB
scaling
PE via DIN-RAIL
3
4
1
5
15
Ready
Enable
Direction
digital output
USB type B
PAM-195-P-S3
6
9
14
10
13
Feedback
Valve
adaption
digital input
x
u
Power
supply
8
GND
Control program
Ramp
function
Demand
Power
limitation
DC
DC
C
Direction / Activation
Power
stage
ia
ib
2
to solenoidA
to solenoid B
Differential input
w
12
Reference
voltage
11
scaling
digital input
Input
7
Input
Page 16 of 35 PAM-195-P-S3 05.06.2020
4.6 Typical wiring
Enable
8765
16151413
1211109
Analoger Sollwert /
Analogue command signal
Magnet A/
SolenoidA
4321
0V
Schirm/
Screen
PE
Spannungsversorgung /
Power Supply
0V
12 V / 24 V
Magnet B /
Solenoid B
+
V ref.
PE
Direction
Ready
Analoges Sensorsignal /
Analogue feedback signal
+
-
0V
Page 17 of 35 PAM-195-P-S3 05.06.2020
4.7 Input connection (examples)
3
4
1
2
solenoid-A
solenoid-B
3 wire connection e.g. for HAWE valves
AIN:W 1000 1000 0 V ( -100... 100%)
+In PIN 9
SPS / PLC -10... 10 V / -100... 100%
-In PIN 10
8V PIN 12
GND PIN 11
+In PIN 9
-In PIN 10
Potentiometer / Joystick
+In PIN 9
-In PIN 10
4... 20 mAinput
AIN:W 1250 1000 2000 C ( 0... 100%)
AIN:W 2500 1000 6000 C ( +/-100%)
AIN:W 1000 800 0 V ( 0... 100%)
AIN:W 2000 800 4000 V ( +/-100%)
0... 10 V to +/- 100% with polarity switch
+In PIN 9
-In PIN 10
GND PIN 11
AIN:W 1000 1000 0 V (= 0... 100%)
PIN 6 (24 V input) (=-0... -100%)
+In PIN 9
PIN 6 (24 V input) (0... -100%)
4... 20 mA input (with polarity switch)
AIN:W 1250 1000 2000 C (0... 100%)
Page 18 of 35 PAM-195-P-S3 05.06.2020
4.8 Technical data
Power supply (Ub)
Power consumption max.
External fuse
[VDC]
[mA]
[A]
12… 30 (incl. ripple)
60 + solenoid current
3 medium time lag
Reference output
Voltage
Maximum load
[V]
[mA]
8
25
Digital inputs
OFF
ON
Input resistance
[V]
[V]
[kOhm]
< 2
> 10
25
Digital outputs
OFF
ON
Maximum output current
[V]
[V]
[mA]
< 2
max. Ub
50
Analog inputs:
Voltage
Input resistance
Current
Burden
Signal resolution
[V]
[kOhm]
[mA]
[Ohm]
[%]
Unipolar/differential
0… 10
min. 90
4… 20
390
0,03
PWM power outputs
Maximum output current
Frequency
[A]
[Hz]
broken wire and short circuit monitored
2.6
61… 2604 selectable in steps
Sample times
Current controller
Analog inputs
[µs]
[ms]
125
1
Serial interface
Transmission rate
-
[kBaud]
USB - virtual COM Port
9,6… 115,2
Housing
Material
Flammability
-
[class]
Snap-on module to EN 50022
PA 6.6 polyamide
V0 (UL94)
Weight
[kg]
0,190
Connections
Communication
Plugs
PE
-
USB type B
4pol. screw terminals
PE: direct via DIN rail
Protection class
Temperature range
Storage temperature
Humidity
Vibration
[°C]
[°C]
[%]
-
IP20
-20… 60
-20 …70
<95 (not condensing)
IEC 60068-2-6 (category C)
EMC
EN 61000-6-2: 8/2005
EN 61000-6-4: 6/2007 ; A1:2011
Page 19 of 35 PAM-195-P-S3 05.06.2020
5 Parameter
5.1 Parameter list
Group
Command
Default
Unit
Description
Basic parameters
LG
EN
-
Changing language help texts
MODE
STD
-
Parameter view
AINMODE
EASY
-
Input scaling mode
SENS
AUTO
-
Malfunction monitor
CCMODE
OFF
-
Activation and deactivation of the characteristic linearization
SOLENOIDS
2
-
Number of solenoids
POL
+
-
Output polarity
Input signal adaptation
Command signal scaling
SIGNAL:W
U0-10
-
Type of input
AIN:W
A: 1000
B: 1000
C: 0
X: V
Free scaling of the analogue command signal input. Gets acti-
vated when AINMODE is switched over to MATH.
SYS_RANGE
100
bar
System pressure
Sensor signal scaling
SIGNAL:X
U0-10
-
Type of input
AIN:X
A: 1000
B: 1000
C: 0
X: V
Free scaling of the analogue feedback input. Gets activated
when AINMODE is switched over to MATH.
N_RANGE:X
100
bar
Sensor nominal pressure
OFFSET:X
0
mbar
Sensor offset
Ramp function
RA:1
RA:2
RA:3
RA:4
100
100
100
100
ms
ms
ms
ms
Command signal four quadrant ramp times
Power limitation function
PLV:A
PLV:B
10000
10000
0.01 %
0.01 %
Power limitation factor
PLT1:A
PLT1:B
5000
5000
0.1 ma
0.1 ms
Dynamic of the power limitation
Page 20 of 35 PAM-195-P-S3 05.06.2020
Group
Command
Default
Unit
Description
Output signal adaptation
CC
-
xy
Free definable characteristic linearization
MIN:A
MIN:B
0
0
0.01 %
0.01 %
Deadband compensation
MAX:A
MAX:B
10000
10000
0.01 %
0.01 %
Output scaling
TRIGGER
200
0.01 %
Deadband compensation trigger point
Parameters of the power stage
CURRENT
1000
mA
Rated solenoid current
DAMPL
500
0.01 %
Dither amplitude
DFREQ
121
Hz
Dither frequency
PWM
2604
Hz
PWM frequency
ACC
ON
-
Current loop auto adjustment
PPWM
IPWM
7
40
-
-
P-Gain of the current loop
I-Gain of the current loop
Table of contents
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