speed control unit for cylinder drives - w.e.st · speed control unit for cylinder drives . ... (in...

W.E.ST. Elektronik GmbH

Technical Documentation

SCU-129-A

SCU-129-I

Speed control unit for cylinder drives


of 31 SCU-129-*-1121 27.06.2012

CONTENTS

1 General Information ............................................................................................................................................. 3

1.1 Order number .............................................................................................................................................. 3

1.2 Scope of supply ........................................................................................................................................... 3

1.3 Accessories ................................................................................................................................................. 3

1.4 Symbols used .............................................................................................................................................. 4

1.5 Legal notice ................................................................................................................................................. 4

1.6 Safety instructions ....................................................................................................................................... 5

2 Characteristics ..................................................................................................................................................... 6

2.1 Device description ....................................................................................................................................... 7

3 Use and application ............................................................................................................................................. 8

3.1 Installation instructions ................................................................................................................................ 8

3.2 Typical system structure .............................................................................................................................. 9

3.3 Method of operation ................................................................................................................................... 10

3.4 Commissioning .......................................................................................................................................... 11

4 Technical description ......................................................................................................................................... 12

4.1 Input and output signals ............................................................................................................................. 12

4.2 LED definitions ........................................................................................................................................... 13

4.3 Circuit diagram ........................................................................................................................................... 14

4.4 Typical cabling ........................................................................................................................................... 15

4.5 Connection examples ................................................................................................................................ 15

4.6 Technical data ........................................................................................................................................... 16

5 Parameters ........................................................................................................................................................ 17

5.1 Parameter overview ................................................................................................................................... 17

5.2 Parameter description ................................................................................................................................ 18

5.2.1 LG (Changing the language for the help texts) ................................................................................. 18

5.2.2 MODE (Switching between parameter groups) ................................................................................. 18

5.2.3 OUTPUT (Characteristic of the output signal.) .................................................................................. 18

5.2.4 STROKE (full stroke)......................................................................................................................... 19

5.2.5 POS 1 (Start-Position)....................................................................................................................... 19

5.2.6 POS 2 (End-Position) ........................................................................................................................ 19

5.2.7 VRAMP (Ramp time for external speed demand) ............................................................................. 19

5.2.8 VMAX (Maximum speed in NC Mode ) ............................................................................................. 19

5.2.9 EOUT (Output signal: READY = OFF) .............................................................................................. 20

5.2.10 POL (Output polarity) ........................................................................................................................ 20

5.2.11 SENS (Module monitoring) ............................................................................................................... 20

5.2.12 AIN (Analog input scaling) ................................................................................................................. 21

5.2.13 A (Acceleration time) ......................................................................................................................... 22

5.2.14 D (Deceleration /braking distance) .................................................................................................... 22

5.2.15 V0 (Loop gain setting) ........................................................................................................................ 22

5.2.16 CTRL (Deceleration function characteristic) ...................................................................................... 23

5.2.17 HAND (Manual speed) ...................................................................................................................... 24

5.2.18 MIN (Overlap compensation) ............................................................................................................ 25

5.2.19 MAX (Limitation) ............................................................................................................................... 25

5.2.20 TRIGGER (Response threshold for the MIN parameter)................................................................... 25

5.2.21 INPOS (In position window) .............................................................................................................. 26

5.2.22 PROCESS DATA (Monitoring) .......................................................................................................... 26

6 Appendix ............................................................................................................................................................ 27

6.1 Failure monitoring ...................................................................................................................................... 27

6.2 Trouble shooting ........................................................................................................................................ 27

6.3 Description of the command structure ....................................................................................................... 29

7 Notes ................................................................................................................................................................. 30


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1 General Information

1.1 Order number

SCU-129-A-11211 - with analogue ±10 V differential output and analogue sensor interface

SCU-129-I-1121 - with analogue 4… 20 mA output and analogue sensor interface

1.2 Scope of supply

The scope of supply includes the module including 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 separate-ly. This documentation can be downloaded as a PDF file from www.w-e-st.de.

1.3 Accessories

RS232-SO - Programming cable with RS232C interface

USB-SO - Programming cable with USB interface

WPC-300 - Start-Up-Tool (downloadable – products/software)

1 The number of the version consists of the hardware-version (first two digits) and the software-version (second two

digits). Because of the development of the products these numbers can vary. They are not strictly necessary for the order. We will always deliver the newest version.


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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.: +49 (0)2163 577355-0

Fax.: +49 (0)2163 577355 -11

Home page: www.w-e-st.de or www.west-electronics.com

EMAIL: [email protected]

Date: 27.06.2012

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 in-ferred from this document. We reserve the right to make technical modifications due to further develop-ment 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 copyright.


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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 protection) must be complied with.

These modules are designed for hydraulic applications in open or closed-loop control cir-cuits. 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 elec-tronics must only be carried out whilst the equipment is switched off and not under pres-sure.

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 commis-sioning instructions must be followed. Guarantee and liability claims are invalid if the in-structions 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, con-tamination 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 electronic module has been developed for controlling hydraulic cylinder drives in closed loop speed control mode. Proportional valves with integrated or external electronics can be controlled with the differ-ential output.

The internal profile generation is optimized for speed control. The controller and the controller setting are adapted to typical requirements and thus permit rapid and uncritical optimization of the control behavio-r.

The module works internally as a position control module in NC mode. A speed profile is generated and the axis is driving with this command speed. This concept is the most robust speed controller for cylinder drives.

Setting up this module is simple and easy to handle with our WPC-300 start-up software.

Typical applications: Speed controlled cylinder drives.

Features

• Analoge speed inputs

• Analoge feedback position sensor

• Parametrized in mm and mm/s

• Internal profile definition by acceleration, velocity and deceleration

• NC profile generator for constant speed

• Usable with overlapped proportional valves and with zero lapped control valves

• Fault diagnosis and extended function checking

• Simplified parametrization with WPC-300 software version 3.2


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2.1 Device description

V:ID:

Add.:Date:

Made in Germany

W.E.ST.

Ready

Status

1 2 3 4

5 6 7 8

9 10 11 12

14 15 1613

D-41372 NiederkrüchtenHomepage: http://www.w-e-st.de

W.E.ST. Elektronik

13 14 15

9 10 11 12

16

Klemmblöcke (steckbar)Terminals (removable)

LEDs

RS232C Interface

Typenschild und AnschlussbelegungType plate and terminal pin assignment

23,0000 mm99,0000 mm

114,0000 mm


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3 Use and application

3.1 Installation instructions

• 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 control modules.

• Typical installation location: 24 V control signal area (close to PLC) The devices must be arranged in the control cabinet so that the power section and the signal sec-tion are separate from each other. Experience shows that the installation space close to the PLC (24 V area) is most suitable. All digital and analog 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 wiring scheme is recommended. The following points must be observed when wiring:

• The signal cables must be laid separately from power cables.

• Analog signal cables must be screened.

• All other cables must be screened if there are powerful interference sources (frequen-cy 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 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 – the manufacturer should be consulted if necessary.

• A low-resistance connection between PE and the mounting rail should be provided. Transient in-terference 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 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 Typical system structure

This minimal system consists of the following components:

(*1) Proportional valve (or control valve): the valve type determines the precision. It is expedient to use control valves with integrated electronics.

(*2) Hydraulic cylinder (with servo seals)

(*3) SCU-129-A control module

(*4) Interface to PLC with analog and digital signals

(*5) Integrated analog position sensor (alternatively also with external measurement system)


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3.3 Method of operation

This control module supports simple point-to-point positioning between the start position POS 1 and the end position POS 2 with hydraulic drives. The module works in NC modus, therefore the speed is con-trolled. The external input is used as the input speed.

Sequence:

The positioning procedure is controlled by the speed input (PIN 9/10). After the release (ENABLE) is ap-plied the command position is set in the module and the drive remains stationary under control at the cur-rent position. The general readiness for operation is now reported via the READY output.

The START signal activates the analogue speed input (PIN 9/10). The drive moves directly (with the de-fined speed) to one of the programmed positions and reports reaching the position via the InPos output. The InPos output remains active as long as the position is maintained and as long as the START signal remains applied.

In manual mode (START disabled) the drive can be moved by means of HAND+ or HAND–. The drive moves under open loop control at the programmed manual speeds. When the HAND (+ or -) signal is switched off, the current actual position is accepted as the required position and the drive comes to a con-trolled stop.

V+

V+

A:A D:A

A:BD:B

MAX:A

MAX:B

driving out

volumetric flow P-A and B-T

control direction

control direction

driving in


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3.4 Commissioning

Step Task

Installation Install the device in accordance with the circuit diagram. Ensure it is wired correct-ly and that the signals are well shielded. The device must be installed in a metal 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 cabling. Switch the device off immediately and check the cabling.

Setting up communication Once the power input is correct the PC (notebook) should be connected to the se-rial interface. Please see the WPC-300 program documentation for how to set up communication.

Further commissioning and diagnosis are supported by the operating software.

Pre-parametrization Now set up the following parameters (with reference to the system design and cir-cuit diagrams): The STROKE, SENSOR SETTING, POLARITY and ACCELERATION. Pre-parametrization is necessary to minimize the risk of uncontrolled movements.

Parametrize specific settings for the control element (MIN for following error com-pensation and MAX for maximum velocity).

Control signal Check the control signal with a voltmeter. The control signal (PIN 15 to PIN 16) lies in the range of ± 10 V. In the current state it should be 0 V. Alternatively, if current signals are used, approx. 0 mA should flow. CAUTION! This signal depends on the EOUT setting.

Switching on the hydrau-lics

The hydraulics can now be switched on. Since the module is not yet generating a signal the drive should be at a standstill or drift slightly (leave its position at a slow speed).

Activating ENABLE CAUTION! The drive can now leave its position and move to an end position at full speed. Take safety measures to prevent personal injury and damage.

The drive is in the current position (with ENABLE the actual position is accepted as the required position). Should the drive move to an end position the polarity is probably wrong.

Activating START With the start signal the demand value of the analog speed value input is accept-ed and the axis moves in direction of the predefined target position. If START is disabled, the axis stops in the preset deceleration distance D:S.

Manual (HAND) operation If START is disabled, the axis can be moved manually with HAND+ or HAND- . After disabling the HAND signal, the axis stops in a controlled manner at the cur-rent position.

Optimize controller Now optimize the controller parameters according to your application and your requirements.


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4 Technical description

4.1 Input and output signals

Connection Supply

PIN 3 Power supply (see technical data)

PIN 4 0 V (GND) connections. Caution, PIN 4 is connected internally to PIN 11 and also to PIN 12.

Connection Analog signals

PIN 9 / 10 Speed and direction command value, range +/- 100 % corresponds to +/- 20 mA

PIN 14 Analogue position actual value (X), range 0… 100 % corresponds to 0… 10 V or 4… 20 mA

PIN 11 / 12 Potential for analogue feedback and command signals.

PIN 15 / 16 Differential output (U) ± 100 % corresponds to ± 10 V (0… 10 V at PIN 15 and PIN 16) or 0… 100% are corresponding to 0… 10 V (PIN 15 and PIN 12), Depending on OUTPUT.

I Version: ± 100 % corresponds to 4… 20 mA (PIN 15 to PIN 12) or 0… 100 % are corre-sponding to 4… 20 mA, depending on the OUTPUT command. A signal lower than 4 mA indicates that there is an error and the module has not been ena-bled. It must be ensured that the valve switches off at < 4 mA.

Connection Digital inputs and outputs

PIN 8 Enable input:

This digital input signal initializes the application. The controller and the READY signal are activated. The output signal to the control element is enabled. The actual current position is accepted as the command position and the drive remains sta-tionary under control at the current position.

If the input is disabled, the output (control signal) is switched off. Take care off the EOUT command!

PIN 7 START (RUN) input:

The position controller is active and the external analog demand position is accepted as the demand value. If the input is disabled during the movement, the system is stopped within the preset distance of D:S.

PIN 6 HAND + input:

Manual operation (START = OFF): the drive moves at the programmed speed in the pro-grammed direction. After deactivation, the actual current position is accepted as the de-mand position. The START (RUN) input has priority over the HAND+ input.

If the sensor signal is missing (external ENABLE signal = ON), the drive can be operated in manual mode.

PIN 5 HAND - input:

Manual operation (START = OFF); the drive moves at the programmed speed in the pro-grammed direction. After deactivation the actual current position is accepted as the required position. The START (RUN) input has priority over the HAND- input.

If the sensor signal is missing (external ENABLE signal = ON), the drive can be operated in manual mode.

PIN 1 READY output:

ON: The module is enabled; there are no discernable errors.

OFF: Enable (PIN 8) is disabled or an error (sensor or internal error) has been detected.

PIN 2 STATUS output:

ON: INPOS message. The axis is within the INPOS window.

OFF: INPOS message. The axis is outside the INPOS window.


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4.2 LED definitions

LEDs Description of the LED function

GREEN Identical to the READY output.

OFF: No power supply or ENABLE is not activated

ON: System is ready for operation

Flashing: Error discovered (valve solenoid or 4… 20 mA).

Only active when SENS = ON.

YELLOW Identical to the STATUS output.

OFF: The axis is outside the INPOS window.

ON: The axis is within the INPOS window.


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4.3 Circuit diagram

PIN

15 =

+, P

IN 1

2 =

GN

D

Com

mand

s:-

PO

S1

- P

OS

2

Po

siti

on

PE

via

DIN

-RA

IL

15

16

12 1 2

Outp

ut: A

Outp

ut: B

8 5

Ready

InP

os

Enable

Sta

rt

24 V

ou

tpu

t

24 V

ou

tpu

t

3,5

mm

JIS

C-6

560 B

uch

se

Diff

ere

ntia

lIn

put

SC

U-1

29

714

0 V

11

Feedback

Posi

tion

Ou

tpu

t Ad

apta

tio

n

Hand -

24 V

inp

ut

24 V

inp

ut

24 V

inp

ut

ws

x

u

Inte

rnal P

ow

er

3 40 V

10 9

Sp

eed

Com

mands:

- V

RA

MP

+/-

20m

A

Com

mand

speed a

nd

posi

tion

11

Co

ntr

ol p

rog

ram

v

24 V

inp

ut

6H

and +

RS

232

C96

00 B

aud

1 S

top

bit

no

par

ity

Pro

fil G

ener

ato

r

Com

man

ds:

- V

MA

X-

ST

RO

KEV

MO

DE

= N

C

Inp

ut

Sel

ekto

r

Com

man

do:

AIN

:X

0..10V

4..20m

A

0 V

Co

ntr

ol F

un

ctio

n

Com

mand

s:- A

:A a

nd

A:B

- V

0:A

and V

0:B

Com

man

ds:

- M

IN:A

and

:B-

MA

X:A

and

:B- T

RIG

GE

R-

PO

L

Outputlimitation

DC

DC

24 V

0 V

PE

LV

-

xdw

Speed

Com

mand

s:-

LG- T

S (

sam

ple

tim

e)-

MO

DE

(E

xpert

or

Sta

ndar

d)

- E

OU

T (

Err

or

Mod

e)-

INP

OS

(In

Pos

out

put

)

Com

mand

s:-

SE

NS

- H

AN

D A

/B-

D:S

-


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4.4 Typical cabling

4.5 Connection examples

AIN:X 2000 1600 2000 C( für 0... 100%)

+In PIN 14

PIN 11 (GND)

PLC or feedback 0... 20 mA two-wire system

e.g. 24 V

+In PIN 14

PIN 11 (GND)

AIN:X 2000 1600 2000 C( für 0... 100%)

PLC or feedback 0... 20 mA three-wire system

e.g. 24 V

+In PIN 9

PIN 11 (GND)

PLC or feedback 0... 20 mA two-wire system

e.g. 24 V

+In PIN 10

PIN 11 (GND)

PLC or feedback 0... 20 mA three-wire system

e.g. 24 V

Valve (6 + PE plug) with OBE electronics

PIN 15

PIN 16

PIN 12

0... 10 V feedback signal

+In PIN 14

In PIN 11 (GND)A : 24 V supply

B : 0 V supply

C : GND or enable

D : + differential input

E : - differential input

F : diagnostics

PE -

8765

16151413

1211109

shield

To power amplifier /valve.

PE K

lemm

e

PE K

lemm

eCommand position and speed (+/- 20mA)

power supplyPLC inputs

24V

0V

Ready

InPos

Enable

StartPLC outputsHand+

Hand-

4321

0V

(-10V..10V)

0V

0... 10V / 4... 20mA

0..10V

Feedback input(0... 10V / 4... 20mA)


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4.6 Technical data

Supply voltage Current requirement

External protection

[VDC]

[mA]

[A]

12… 30 (incl. ripple)

< 100

1 medium time lag

Digital inputs

Input resistance

[V]

[V]

[kOhm]

logic 0: < 2

logic 1: > 10

25

Digital outputs [V]

[V]

logic 0: < 2

logic 1: > 12 (50 mA)

Analog inputs (sensor and demand value signal)

Signal resolution

Speed input

Signal resolution

[V]

[mA]

[%]

[mA]

[%]

0… 10; 25 kOhm

4… 20; 250 Ohm

0,01(internally 0,0031) incl. oversampling

+/- 20; 240 Ohm

0,01

Analogue outputs

Voltage

Signal resolution

Current

Signal resolution

[V]

[mA]

[%]

[mA]

[%]

2 x 0… 10; differential output

5 (max. load)

0,024

4… 20; 390 Ohm maximum load

0,024

Controller sample time [ms] 1 (variable from 0,5 … 3 ms)

Serial interface

RS 232C, 9600… 57600 Baud, 1 stop bit, no parity, Echo Mode

Housing Snap-on module to EN 50022

PA 6.6 polyamide

Flammability class V0 (UL94)

Weight [kg] 0,170

Protection class

Temperature range

Storage temperature

Humidity

[°C]

[°C]

[%]

IP20

- 20… 60

-20… 70

< 95 (non-condensing)

Connections RS232C: 3,5 mm JISC-6560

4 x 4-pole terminal blocks

PE: via the DIN mounting rail

EMC

EN 61000-6-2: 8/2002

EN 61000-6-3: 6/2005


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5 Parameters

5.1 Parameter overview

Command Default Unit Description

LG GB - Changing language help texts.

MODE STD - Mode parameter.

OUTPUT BIPOLAR - Characteristics oft he output signal.

STROKE 100 mm Working stroke or the sensor.

POS1 5 mm Start - Position

POS2 95 mm End - Position

VRAMP 200 ms Ramp function for external speed input.

VMAX 50 mm/s Maximum speed in NC mode.

EOUT 0 0,01 % Error output signal.

POL + - Reversal of output polarity.

SENS On - Activation and disabling of internal monitoring functions.

AIN:X

A: 1000

B: 1000

C: 0

X: V

-

-

0,01 %

-

Analogue input scaling for X (actual value).

A:A

A:B

100

100

ms

ms

Acceleration times.

D:S 10 mm Deceleration distance.

V0:A

V0:B

2

2

1/s

1/s

Loop gain setting.

CTRL SQRT1 - Specification of control characteristics.

HAND:A

HAND:B

3330

-3330

0,01 %

0,01 %

Output signal in manual mode.

MIN:A

MIN:B

0

0

0,01 &

0,01 %

Zero point setting /following error compensation.

MAX:A

MAX:B

10000

10000

0,01 %

0,01 %

Maximum output signal limitation.

TRIGGER 200 0,01 % Trigger threshold for activating the following error compensation (MIN).

INPOS 200 µm Range for InPos signal.


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5.2 Parameter description

5.2.1 LG (Changing the language for the help texts)

Command Parameters Unit Group

LG x x= DE|GB - STD

Either German or English can be selected for the help texts.

CAUTION: After changing the language settings the ID button (SPEED BUTTON) in the menu bar (WPC-300) must be pressed (module identification).

5.2.2 MODE (Switching between parameter groups)


MODE x x= STD|EXP - STD

This command changes the operating mode. Various commands (defined via STD/EXP) are blanked out in Standard Mode. The commands in Expert Mode have a more significant influence on system behavior and should accordingly be changed with care.

5.2.3 OUTPUT (Characteristic of the output signal.)


OUTPUT X x= UNIPOL|BIPOL - STD

With this command the character of the output signal can be defined.

A-version:

UNIPOL: Analogue voltage output signal 0... 10V for 0… 100% (PIN 15 against PIN 11)

BIPOL: Differential voltage output signal ±10V for ±100% (between PIN 15 and PIN 16)

I-version:

UNIPOL: Analogue current output signal 4… 20mA for 0…100% (PIN 15 against PIN 11)

BIPOL: Analogue current output signal 4… 20mA for ±100% (PIN 15 against PIN 11)


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5.2.4 STROKE (full stroke)


STROKE X x= 10… 10000 mm STD

This command defines the full stroke, which corresponds to 100 % of the input signal. If the demand is set incorrectly, this leads to incorrect system settings, and the dependent parameters such as speed and gain cannot be calculated correctly.

5.2.5 POS 1 (Start-Position)

5.2.6 POS 2 (End-Position)


POS1 X

POS2 X

x= 1… 10000

x= 1… 10000

mm

mm

STD

STD

The start and end position will be set with this parameter. The axis will drive between these both positions with the controlled speed. The direction and therefore the POS 1 or POS 2 value is selected by the polari-ty of the speed input signal.

The InPos output can be used to detect the end of the movement (stroke of the cylinder).

5.2.7 VRAMP (Ramp time for external speed demand)


VRAMP X x= 1… 2000 ms EXP

The rate of change of the external speed demand can be limited by this ramp time. The command is only.

5.2.8 VMAX (Maximum speed in NC Mode )


VMAX X x= 1… 5000 mm/s EXP

Specification of the maximum speed in NC mode. This value is defined by the drive system and should be specified as precisely as possible (not too high under any circumstances). The maximum speed is scaled by means of the VELO value or via the external speed demand. The command is only active if the VMODE has been parametrized to NC.


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5.2.9 EOUT (Output signal: READY = OFF)


EOUT X x= -10000… 10000 0,01 % EXP

Output value in case of a detected error or a deactive ENABLE input. A value (degree of valve opening) for use in the event of a sensor error (or the module is disabled) can be defined here. This function can be used if, for example, the drive is to move to one of the two end positions (at the specified speed) in case of a sensor error.

|EOUT| = 0 The output is switched off in the event of an error. This is normal behavior.

CAUTION! If the output signal is 4… 20 mA, the output is switched off if |EOUT| = 0. If a null value = 12 mA is to be output in the event of an error, EOUT must be set to 1.

CAUTION! The output value defined here is stored permanently (independently of the pa-rameter set). The effects should be analyzed by the user for each application from the point of view of safety.

5.2.10 POL (Output polarity)


POL X x= +|- - STD

This command enables the output signal polarity to be reversed.

5.2.11 SENS (Module monitoring)


SENS x x= ON|OFF - STD

This command is used to activate and disable monitoring functions (4… 20 mA sensors, solenoid current flow monitoring and internal module monitoring).

Normally, monitoring is always active as otherwise no errors are signalled via the PIN 1 (READY) output. It can, however, be disabled for fault finding.


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5.2.12 AIN (Analog input scaling)


AIN:X a= -10000… 10000

b= -10000… 10000

c= -500… 10000

x= V|C

-

-

0,01 %

-

STD

This command can be used to scale the individual inputs. The following linear equation is used for scal-ing.

)( cInputb

aOutput −=

The “c” value is the offset (e. g. to compensate the 4 mA in case of a 4… 20 mA input). The variables a and b define the gain factor. e. g.: 2,345 correspond to: a = 2345, b =1000

The internal measuring resistor for measuring the current (4… 20 mA) is activated via the x value and the evaluation switched over accordingly.

Typical settings:

Command Input Description

AIN:X1 1000 1000 0 V 0… 10 V Range: 0… 100 %

AIN:X1 10 8 1000 V OR

AIN:X1 1000 800 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:X1 10 4 500 V OR

AIN:X1 1000 400 500 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:X1 20 16 2000 C OR

AIN:X1 2000 1600 2000 C OR

AIN:X1 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 parametrization for 4… 20 mA is setting the range to 0… 100 %.


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5.2.13 A (Acceleration time)


A:I X i= A|B

x= 1… 5000

ms

ms

STD

Ramp function for the 1st and 3

rd quadrant.

The acceleration time for positioning is dependent on the direction. A corresponds to connection 15 and B corresponds to connection 16 (if POL = +). Normally A = flow P-A, B-T and B = flow P-B, A-T.

For quadrants 2 and 4, parameters D:A and D:B are used as the deceleration distance demand.

5.2.14 D (Deceleration /braking distance)


D:S X x= 1… 10000 mm STD

This parameter is specified in mm.

Parameter D:S is used as the emergency stopping ramp when disabling the START signal. After disabling, a new target position (current position plus D:S) is calculated in relation to the speed and is specified as command value.

5.2.15 V0 (Loop gain setting)


V0:I X i= A|B

x= 1… 200

s-1

s-1

EXP

This parameter is specified in s-1

(1/s). In NC mode the loop gain is normally specified rather than the deceleration distance

2.

The internal gain is calculated from this gain value together with the VMAX and POSITION parameters.

Calculation of the internal control gain

In NC mode the following error at maximum speed is calculated by means of the loop gain. This following error corresponds to the deceleration distance with stroke-dependent deceleration. The conversion and therefore also the correct data demands related to the control system are relatively simple if the relation-ship described here is taken into account.

2 The loop gain is alternatively defined as a KV factor with the unit (m/min)/mm or as Vo in 1/s. The conversion is KV

= Vo/16.67.

i

Intern

i

D

STROKEG

V

vD

=

=

0

max


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5.2.16 CTRL (Deceleration function characteristic)


CTRL X x= lin|sqrt1

|sqrt2

- STD

The deceleration characteristic is set with this parameter. In the case of positively overlapped proportional valves the SQRT function should be used. The non-linear flow function of these valves is linearized by the SQRT

3 function.

In the case of zero lapped valves (control valves and servo valves) the LIN or SQRT1 function should be used regardless of the application. The progressive characteristic of the SQRT1 function has better posi-tioning accuracy but can also lead to longer positioning times in individual cases.

LIN: Linear deceleration characteristic (gain is increased by a factor of 1).

SQRT1: Root function for braking curve calculation. The gain is increased by a factor of 3 (in the target position). This is the default setting.

SQRT2: Root function for braking curve calculation. The gain is increased by a factor of 5 (in the target position). This setting should only be used with a significantly progressive flow through the valve.

3 The SQRT function generates constant deceleration and thus reaches the target position faster. This is achieved by

increasing the gain during the deceleration process.

1 Braking function with respect to stroke and time

Stroke

Velo

city

Braking strokeD:A or D:B

CTRL = LIN

CTRL = SQRT

Time

Velo

city

Deceleration timeD:A or D:B

CTRL = LIN

CTRL = SQRT


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5.2.17 HAND (Manual speed)


HAND:I X i= A|B

x= -10000… 10000

0,01 %

0,01 %

STD

The manual speeds are set with these parameters. Entering the speed and direction at will enables any switch input to be assigned.

The drive moves in a controlled manner in the defined direction when the manual signal is active. After the manual signal has been disabled, the drive remains under control in the current position.

In the event of a fault (position sensor fault) the drive can still be moved with the manual function. The valve is no longer driven after the manual signals have been disabled.

The manual speed is limited by the speed demand (MIN evaluation).


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5.2.18 MIN (Overlap compensation)

5.2.19 MAX (Limitation)

5.2.20 TRIGGER (Response threshold for the MIN parameter)


MIN:I X

MAX:I X

TRIGGER X

i= A|B

x= 0… 6000

x= 3000… 10000

x= 0… 4000

-

0,01 %

0,01 %

0,01 %

STD

The output signal to the valve is adjusted by means of these commands. A kinked volume flow character-istic is used instead of the typical overlap step for the position controls. The advantage is a better and more stable positioning behavior. At the same time, kinked volume flow characteristics can also be ad-justed with this compensation

4.

CAUTION: If there should also be adjustment options for dead zone compensation on the valve or valve amplifier, it must be ensured that the adjustment is performed either at the power amplifier or in the module. If the MIN value is set too high, this has an effect on the minimum speed, which can then no longer be adjusted. In extreme cases this leads to oscillation around the controlled position.

MAX:A

MIN:A

MIN:B

MAX:B

Input

Outp

ut flow linearization

standard deadband compensation

TRIGGER value

4 Various manufacturers have valves with a defined linear curve: e. g. a kink at 40 or 60 % (corresponding to 10 %

input signal) of the nominal volume flow. In this case the TRIGGER value should be set to 1000 and the MIN value to 4000 (6000).

If zero lapped or slightly underlapped valves are used, the volume flow gain in the zero range (within the underlap) is twice as high as in the normal working range. This can lead to vibrations and jittery behavior. To compensate for this, the TRIGGER value should be set to approximately 200 and the MIN value to 100. The gain in the zero point is thus halved and a higher overall gain can often be set.


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5.2.21 INPOS (In position window)


INPOS X x= 2… 10000 µm STD

This parameter is entered in µm. The INPOS command defines a monitoring window in which the INPOS message is displayed. The moni-toring window is placed centrally on the required position value. The actual position value within this win-dow is signalled by the INPOS message at the status output (see Pin description). The positioning pro-cess is not influenced by this message. The control remains active. In NC mode this message is used to monitor the following error (depending on the parametrization).

5.2.22 PROCESS DATA (Monitoring)

Command Parameters Unit

WA

W

X

XD

V

U

Demand value (input signal)

Demand value (according to the profile generator)

Actual value

Error variable

Speed demand

Control signal

mm

mm

mm

mm

%

%

The process data are the variables which can be observed continuously on the monitor or on the oscillo-scope.


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6 Appendix

6.1 Failure monitoring

Following possible error sources are monitored continuously:

Source Fault Characteristic

Feedback PIN 14, 4...20 mA Out of range The power stage is deactivated.

EEPROM (at switching on)

Data error The power stage is deactivated.

The module can be activated by saving new parameters (press-ing of the SAVE Button).

Attention: Take care of the setting of the EOUT command.

6.2 Trouble shooting

It is assumed that the device is in an operable state and there is communication between the module and the WPC-300. Furthermore, the valve control parametrization has been set with the assistance of the valve data sheets.

The RC in monitor mode can be used to analyze faults.

CAUTION: All safety aspects must be thoroughly checked when working with the RC (Re-mote Control) mode. In this mode the module is controlled directly and the machine control cannot influence the module.

FAULT CAUSE / SOLUTION

ENABLE is active, the module does not re-spond, and the READY LED is off.

There is presumably no power supply or the ENABLE signal (PIN 8) is not present.

If there is no power supply, there is also no communication via our operating pro-gram. If a connection has been made to the WPC-300, then a power supply is also available

If the power supply exists, an attempt should be made to see whether the system can be moved by means of the HAND+ and HAND- inputs (measuring the output signal to the valve helps).

ENABLE is active, the READY LED is flashing.

The flashing READY LED signals that a fault is been detected by the module. The fault could be:

• A broken cable or no signal at the input (PIN 14), if 4… 20 mA signals are parametrized.

• Internal data error: press the command/button SAVE to delete the data er-ror. The system reloads the DEFAULT data.

With the WPC-300 operating program the fault can be localised directly via the moni-tor.

ENABLE is active; the READY LED is on, the system moves to an end position.

The control circuit polarity is incorrect. The polarity can be changed with the POL command or by reversing the connections to PIN 15 and PIN 16.


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ENABLE is active, the READY LED is on, the STATUS LED is off, the system moves to the target position but doesn’t reach it (posi-tioning error).

Serious positioning errors can result from incorrect parametrization or incorrect sys-tem design.

• Is the cylinder position specified correctly?

• What about the Vo gain? The gain should be calculated for the right range of values.

• Is the valve a zero lapped control valve or a standard proportional valve? In the case of a proportional valve, the valve overlap which may be present should be compensated for with the MIN parameters. Typical values are to be found in the valve data sheet.

ENABLE is active, the READY LED is on, and the system oscillates on the spot.

The system is working and also actuating the valve.

Various potential problems could be:

• The parametrization is not yet adjusted to the system (gain too high).

• There is severe interference on the power supply.

• Very long sensor cables (> 40 m) and sensor signal interference.

• The MIN setting to compensate the valve overlap is too high.

As a basic principle, the parametrization of the sensor data and the controller set-tings must be carried out first (before switching on). An incorrect demand is equiva-lent to incorrect system design which then leads to incorrect operation. If the system oscillates, the gain should first be reduced (longer deceleration distances for D:A and D:B) and in the case of overlapped valves the MIN parameter should also be re-duced.

Speed too low The drive may be able to move to position but the speed is too low.

• Check the control signal to the valve.

• Via the integrated oscilloscope (U variable).

• Measure the signal to the valve with an external oscilloscope / voltmeter.

• If the control is within the range of ± 100 %, the fault must be sought in the hydraulics.

• If the control signal is relatively low, the following points should be checked:

• Is the internal/external speed signal limiting the speed?

• Which setting has been specified for the Vo gain?

Speed too high The drive should move to position. The drive moves in and out too fast leading to un-controlled behavior. Reducing the speed (VMAX parameter) has very little or no ef-fect.

• The hydraulic system is over-sized5. The entire parametrization of the

movement cycle cannot be reproduced (overlap and deceleration distance settings)

5 The nominal volume flow for hydraulic proportional valves is normally stated in L/min. This nominal volume flow is

measured for each control edge at a pressure drop of 5 bar. For a system with higher pressure (e. g. 100 bar), the volume flow is (theoretically) approx. three times higher. This theoretically calculated higher value defines the sys-tem’s volume flow gain and thus the control behavior. If the volume flow is limited by the oil supply, for example, alt-hough the maximum speed is not three times faster, the volume flow is only reduced after a significant reduction (30 % control signal). The system is critically oversized if the theoretical maximum speed is 1,73 times greater than the required speed.


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6.3 Description of the command structure

The command structure:

[nnnn:i x] or

[nnnn x]

Meaning:

nnnn - used for an arbitrary command name

nnnn: - used for an arbitrary command name, expandable by an index.

i oder I - a dummy is for the index. E. g. an index can be „A“ or „B“, depending on the direction.

x - parameter value, in case of special commands more than one parameter are possible.

Examples:

MIN:A 2000 nnnn = “MIN”, i = “A” and x = “2000”

OFFSET 50 nnnn = „OFFSET“ and x = „50“

C:IC 2000 nnnn = “C”, i = “IC” and x = “2000”


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7 Notes

speed control unit for cylinder drives - w.e.st · speed control unit for cylinder drives . ... (in...

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