Siemens SIWAREX WP321 User manual

SIWAREX WP321
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Weighing systems
Electronic weighing system
SIWAREX WP321
Manual
07/2014
A5E33715669A-02
Introduction
1
Safety notes
2
Description
3
Application planning
4
Mounting
5
Connection
6
Commissioning
7
Scale parameters and
functions
8
Messages
9
Command lists
10
Communication in SIMATIC
S7-300/1200/1500
11
Technical data
12
Accessories
13
Appendix
A
ESD guidelines
B
List of abbreviations
C

Siemens AG
Division Digital Factory
Postfach 48 48
90026 NÜRNBERG
GERMANY
Order number: A5E33715669A
Ⓟ12/2014 Subject to change
Copyright © Siemens AG 2014.
All rights reserved
Legal information
Warning notice system
This manual contains notices you have to observe in order to ensure your personal safety, as well as to prevent
damage to property. The notices referring to your personal safety are highlighted in the manual by a safety alert
symbol, notices referring only to property damage have no safety alert symbol. These notices shown below are
graded according to the degree of danger.
DANGER
indicates that death or severe personal injury
will
result if proper precautions are not taken.
WARNING
indicates that death or severe personal injury
may
result if proper precautions are not taken.
CAUTION
indicates that minor personal injury can result if proper precautions are not taken.
NOTICE
indicates that property damage can result if proper precautions are not taken.
If more than one degree of danger is present, the warning notice representing the highest degree of danger will
be used. A notice warning of injury to persons with a safety alert symbol may also include a warning relating to
property damage.
Qualified Personnel
The product/system described in this documentation may be operated only by
personnel qualified
for the specific
task in accordance with the relevant documentation, in particular its warning notices and safety instructions.
Qualified personnel are those who, based on their training and experience, are capable of identifying risks and
avoiding potential hazards when working with these products/systems.
Proper use of Siemens products
Note the following:
WARNING
Siemens products may only be used for the applications described in the catalog and in the relevant technical
documentation. If products and components from other manufacturers are used, these must be recommended
or approved by Siemens. Proper transport, storage, installation, assembly, commissioning, operation and
maintenance are required to ensure that the products operate safely and without any problems. The permissible
ambient conditions must be complied with. The information in the relevant documentation must be observed.
Trademarks
All names identified by ® are registered trademarks of Siemens AG. The remaining trademarks in this publication
may be trademarks whose use by third parties for their own purposes could violate the rights of the owner.
Disclaimer of Liability
We have reviewed the contents of this publication to ensure consistency with the hardware and software
described. Since variance cannot be precluded entirely, we cannot guarantee full consistency. However, the
information in this publication is reviewed regularly and any necessary corrections are included in subsequent
editions.

SIWAREX WP321
Manual, 07/2014, A5E33715669A-02 3
Table of contents
1 Introduction............................................................................................................................................. 9
1.1 Purpose of the manual..............................................................................................................9
1.2 Basic knowledge required.........................................................................................................9
1.3 Manual - range of validity..........................................................................................................9
2 Safety notes.......................................................................................................................................... 11
2.1 General safety instructions .....................................................................................................11
2.2 IT Security...............................................................................................................................12
3 Description............................................................................................................................................ 13
3.1 Product overview ....................................................................................................................13
3.2 Area of application ..................................................................................................................13
3.3 System integration in SIMATIC...............................................................................................13
3.4 Customer benefits...................................................................................................................15
3.5 Scope of delivery ....................................................................................................................16
4 Application planning.............................................................................................................................. 17
4.1 Functions ................................................................................................................................17
4.2 Parameter assignment options ...............................................................................................18
4.2.1 Parameter assignment with the PC ........................................................................................18
4.2.2 Parameter assignment with the SIMATIC Panel ....................................................................18
5 Mounting............................................................................................................................................... 19
5.1 Installation guideline ...............................................................................................................19
5.2 EMC-compliant setup..............................................................................................................20
5.2.1 Introduction .............................................................................................................................20
5.2.2 Possible effects of interference...............................................................................................20
5.2.3 Coupling mechanisms.............................................................................................................20
5.2.4 Five basic rules for securing EMC ..........................................................................................21
5.3 Mounting on the SIMATIC ET 200SP .....................................................................................23
5.4 Configuration of the hardware in SIMATIC .............................................................................24
6 Connection ........................................................................................................................................... 25
6.1 24 V connection ......................................................................................................................26
6.2 Connecting the load cells........................................................................................................26
6.3 Shield connection....................................................................................................................28
6.4 Connection of RS485 serial interface .....................................................................................29
6.5 Connection of Siebert display via RS485 ...............................................................................30

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SIWAREX WP321
4Manual, 07/2014, A5E33715669A-02
7 Commissioning ..................................................................................................................................... 31
7.1 Factory-set parameters.......................................................................................................... 31
7.2 Commissioning tools.............................................................................................................. 31
7.3 5-minute quick start with the operator panel and the Ready-for-Use software ..................... 32
7.3.1 Start........................................................................................................................................ 32
7.3.2 Factory setting of the parameters .......................................................................................... 33
7.3.3 Selecting the calibration method............................................................................................ 34
7.3.4 Defining the calibration weights ............................................................................................. 35
7.3.5 Setting calibration points........................................................................................................ 36
7.3.6 Calibrating the scale automatically ........................................................................................ 37
7.3.7 Performing the automatic calibration ..................................................................................... 38
7.3.8 Checking the scale following calibration ................................................................................ 38
7.4 5-minute quick start with SIWATOOL .................................................................................... 39
7.4.1 Activate service mode............................................................................................................ 39
7.4.2 Load factory setting................................................................................................................ 39
7.4.3 Input of required parameters.................................................................................................. 40
7.4.4 Complete automatic calibration.............................................................................................. 40
7.4.5 Receive all data...................................................................................................................... 41
7.4.6 Checking the scale following calibration ................................................................................ 41
7.5 Service with the SIWATOOL program ................................................................................... 42
7.5.1 Windows and functions of SIWATOOL.................................................................................. 42
7.5.2 Offline parameter assignment................................................................................................ 43
7.5.3 Online parameter assignment................................................................................................ 43
7.5.4 Available help options ............................................................................................................ 44
7.5.5 Entering parameters with SIWATOOL ................................................................................... 44
8 Scale parameters and functions ............................................................................................................ 45
8.1 Parameters and functions ...................................................................................................... 45
8.2 DR 2 command code ............................................................................................................. 45
8.3 DR 3 calibration parameters .................................................................................................. 46
8.3.1 Scale name ............................................................................................................................ 48
8.3.2 Unit of weight ......................................................................................................................... 48
8.3.3 Gross identifier ....................................................................................................................... 48
8.3.4 Maximum weighing range ...................................................................................................... 49
8.3.5 Calibration weights 0, 1, 2 and calibration digits 0, 1, 2 ........................................................ 49
8.3.6 Scale interval.......................................................................................................................... 49
8.3.7 Automatic zero adjustment .................................................................................................... 49
8.3.8 Decimal places for process values ........................................................................................ 49
8.3.9 Maximum tare load ................................................................................................................ 49
8.3.10 Maximum negative zeroing limit............................................................................................. 50
8.3.11 Maximum positive zeroing limit .............................................................................................. 50
8.3.12 Standstill range ...................................................................................................................... 51
8.3.13 Standstill time......................................................................................................................... 51
8.3.14 Standstill waiting time ............................................................................................................ 52
8.3.15 Low-pass filter limit frequency................................................................................................ 52
8.3.16 Low-pass filter number........................................................................................................... 52
8.3.17 Mean value filter depth........................................................................................................... 53

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8.4 Calibration procedure..............................................................................................................54
8.4.1 Calibration with calibration weights.........................................................................................54
8.4.2 Automatic calibration...............................................................................................................57
8.5 DR 4 Output of calculated calibration digits............................................................................58
8.5.1 Calibration digits 0, 1, 2 (calculated).......................................................................................58
8.6 DR 5 zeroing memory.............................................................................................................59
8.6.1 Effective tare weight - from specification ................................................................................60
8.6.2 Effective tare weight (semi-automatic)....................................................................................60
8.6.3 Zero weight (semi-automatic) .................................................................................................60
8.6.4 Current zero tracking weight...................................................................................................60
8.6.5 Dead load................................................................................................................................60
8.7 DR 6 limit value settings .........................................................................................................61
8.7.1 Limit value 1 ON, limit value 2 ON, limit value 1 OFF, limit value 2 OFF ...............................63
8.7.2 Limit value "Empty" ON...........................................................................................................63
8.7.3 Delay time for limits.................................................................................................................64
8.8 DR 9 module information ........................................................................................................65
8.9 DR 10 load cell parameters ....................................................................................................67
8.9.1 50/60 Hz toggling ....................................................................................................................68
8.9.2 Number of support points .......................................................................................................68
8.9.3 Load cell characteristic value..................................................................................................68
8.9.4 Rated load of a load cell .........................................................................................................68
8.10 DR 13 RS485 parameters ......................................................................................................69
8.10.1 RS485 protocol .......................................................................................................................70
8.10.2 RS485 baud rate.....................................................................................................................70
8.10.3 RS485 character parity ...........................................................................................................70
8.10.4 Decimal place for Siebert indicator .........................................................................................70
8.11 DR 14 SIMATIC interface parameters ....................................................................................71
8.11.1 Selection of process value 1, 2...............................................................................................72
8.12 DR 15 manual tare specification.............................................................................................73
8.12.1 Specification of tare weight.....................................................................................................73
8.13 DR 30 current process values ................................................................................................74
8.13.1 Gross process weight .............................................................................................................76
8.13.2 Net process weight .................................................................................................................76
8.13.3 Tare process weight................................................................................................................76
8.13.4 Gross / net weight ...................................................................................................................76
8.13.5 Gross / net weight with increased resolution (x 10)
................................................................76
8.13.6 Tare weight .............................................................................................................................76
8.13.7 Refresh counter for process values ........................................................................................76
8.14 DR 31 advanced current process values................................................................................77
8.14.1 Unfiltered digit value ...............................................................................................................77
8.14.2 Filtered digit value...................................................................................................................77
8.14.3 Refresh counter for process values ........................................................................................78
8.15 DR 32 Message display..........................................................................................................79
8.15.1 Error bytes 0 to 7 ....................................................................................................................81
8.16 DR 34 ASCII main display value.............................................................................................82
8.16.1 Content of main display as ACII string....................................................................................83

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6Manual, 07/2014, A5E33715669A-02
9 Messages ............................................................................................................................................. 85
9.1 Message types ....................................................................................................................... 85
9.2 Message paths....................................................................................................................... 86
9.3 Evaluating messages with the help of SIWATOOL ............................................................... 86
9.4 Detecting messages with the help of FB SIWA ..................................................................... 86
9.5 Message list ........................................................................................................................... 87
9.5.1 System status message list ................................................................................................... 87
9.5.2 Technology error message list............................................................................................... 87
9.5.3 Data and operating errors message list................................................................................. 88
9.5.4 Messages by LEDs on the module ........................................................................................ 89
10 Command lists ...................................................................................................................................... 91
11 Communication in SIMATIC S7-300/1200/1500 .................................................................................... 95
11.1 General information ............................................................................................................... 95
11.2 Structure of the program "Ready for use".............................................................................. 95
11.3 Advantages of task sharing.................................................................................................... 96
11.4 Hardware configuration of the electronic weighing system ................................................... 97
11.5 Calling of function block ......................................................................................................... 99
11.6 Working with the function block ........................................................................................... 100
11.7 I/O interface of function block .............................................................................................. 103
11.8 Error codes of function block ............................................................................................... 103
11.9 Diagnostics messages ......................................................................................................... 104
11.10 Diagnostics interrupts .......................................................................................................... 105
11.11 Hardware interrupts ............................................................................................................. 105
12 Technical data .....................................................................................................................................107
12.1 Technical specifications ....................................................................................................... 107
12.2 Electrical, EMC and climatic requirements .......................................................................... 110
12.3 Approvals ............................................................................................................................. 114
13 Accessories .........................................................................................................................................115
A Appendix .............................................................................................................................................119
A.1 Technical support................................................................................................................. 119
B ESD guidelines ....................................................................................................................................121
B.1 ESD Guidelines.................................................................................................................... 121
C List of abbreviations .............................................................................................................................123
C.1 List of abbreviations ............................................................................................................. 123
Index ...................................................................................................................................................125

Table of contents
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Manual, 07/2014, A5E33715669A-02 7
Tables
Table 6- 1 Connection of the 24 V supply .....................................................................................................26
Table 6- 2 Termination of RS485 serial interface..........................................................................................29
Table 6- 3 Settings of Siebert display S102..................................................................................................30
Table 8- 1 Assignment of data record 3 ........................................................................................................46
Table 8- 2 Assignment of data record 4 ........................................................................................................58
Table 8- 3 Assignment of data record 5 ........................................................................................................59
Table 8- 4 Assignment of data record 6 ........................................................................................................61
Table 8- 5 Assignment of data record 9 ........................................................................................................65
Table 8- 6 Assignment of data record 10 ......................................................................................................67
Table 8- 7 Assignment of data record 13 ......................................................................................................69
Table 8- 8 Assignment of data record 14 ......................................................................................................71
Table 8- 9 Selection table for process value 1,2...........................................................................................72
Table 8- 10 Assignment of data record 15 ......................................................................................................73
Table 8- 11 Assignment of data record 30 ......................................................................................................74
Table 8- 12 Assignment of data record 31 ......................................................................................................77
Table 8- 13 Assignment of data record 32 ......................................................................................................79
Table 8- 14 Assignment of data record 34 ......................................................................................................82
Table 10- 1 Command groups of the SIWAREX WP321................................................................................93
Table 11- 1 Memory requirements of the function block.................................................................................95
Table 11- 2 I/O data of the function block .....................................................................................................103
Table 11- 3 Statuses/errors when working with the function block ...............................................................103
Table 11- 4 Diagnostics messages ...............................................................................................................104
Table 12- 1 Interference emission (industrial area): EN 61000-6-4..............................................................111
Table 12- 2 Interference immunity (industrial environment): EN 61000-6-2 .................................................112
Table 12- 3 Operating conditions to IEC 60721............................................................................................113
Table 12- 4 Climatic requirements ................................................................................................................113
Table 13- 1 Essential accessories ................................................................................................................115
Table 13- 2 Optional accessories..................................................................................................................115

Table of contents
SIWAREX WP321
8Manual, 07/2014, A5E33715669A-02
Figures
Figure 3-1 System overview ..........................................................................................................................14
Figure 4-1 SIWATOOL overview ...................................................................................................................18
Figure 5-1 Installation of the I/O or SIWAREX modules................................................................................23
Figure 6-1 SIWAREX WP321 process terminals on the base unit................................................................25
Figure 6-2 Shielding in the screw gland ........................................................................................................27
Figure 6-3 Shield connection and shield terminal .........................................................................................28
Figure 6-4 Connection of Siebert display S102.............................................................................................30
Figure 7-1 Quick start step 1 .........................................................................................................................32
Figure 7-2 Quick start step 2 .........................................................................................................................33
Figure 7-3 Quick start step 3 .........................................................................................................................34
Figure 7-4 Quick start step 4a .......................................................................................................................35
Figure 7-5 Quick start step 5a .......................................................................................................................36
Figure 7-6 Quick start step 4b .......................................................................................................................37
Figure 7-7 Quick start step 5b .......................................................................................................................38
Figure 7-8 Quick setup with marked parameters ..........................................................................................39
Figure 7-9 Sending/receiving a data record with SIWATOOL V7 .................................................................40
Figure 7-10 Layout of the SIWATOOL user interface .....................................................................................42
Figure 8-1 Standstill monitoring.....................................................................................................................51
Figure 8-2 Step response of the digital low-pass filter when fg = 2 Hz .........................................................52
Figure 8-3 Calibration digits and calibration weight.......................................................................................55
Figure 8-4 Linearizing the scale's characteristic curve..................................................................................56
Figure 8-5 Limit value configuration ..............................................................................................................63
Figure 11-1 Hardware configuration in the TIA Portal .....................................................................................97
Figure 11-2 Start address of module in TIA Portal ..........................................................................................98
Figure 11-3 Configuration of interrupts in TIA Portal.......................................................................................98
Figure 11-4 HW ID of module in TIA Portal.....................................................................................................98
Figure 11-5 Calling of WP321DR block in user program ................................................................................99
Figure 11-6 CMD command mailboxes.........................................................................................................100
Figure 11-7 Configuration of hardware interrupts for S7-1500......................................................................106
Figure B-1 Electrostatic voltages which an operator can be subjected to...................................................122

SIWAREX WP321
Manual, 07/2014, A5E33715669A-02 9
Introduction
1
1.1
Purpose of the manual
This manual contains all the necessary information on setting up, installing, wiring and
commissioning the SIWAREX WP321 electronic weighing system.
1.2
Basic knowledge required
Knowledge of weighing technology as well as general knowledge of the SIMATIC system
including the TIA Portal are necessary in order to understand the manual.
1.3
Manual - range of validity
This manual is valid for:
Type designation
Order No.
as of version
SIWAREX WP321 7MH4138-6AA00-0BA0 HW V.1 FW V. 1.0
Note
This manual contains a description of all electronic weighing systems available at the time
the manual was published. We reserve the right to include a Product Information with the
latest information on the module.

Introduction
1.3 Manual - range of validity
SIWAREX WP321
10 Manual, 07/2014, A5E33715669A-02

SIWAREX WP321
Manual, 07/2014, A5E33715669A-02 11
Safety notes
2
2.1
General safety instructions
WARNING
Non-compliance with warning notes or non-qualified handling of the system
Failure to observe the warning notes or handling of the device/system by non-qualified
personnel can result in serious injury or damage to property. This means only qualified
personnel are permitted to handle this device/system.
WARNING
Permission for installation in machines
Start-up/commissioning is absolutely prohibited until it has been ensured that the machine
in which the component described here is to be installed fulfills the
regulations/specifications of Machinery Directive 89/392/EEC.
Note
The specifications of the manual for the SIMATIC ET 200SP system apply for configuration,
installation and commissioning in the SIMATIC environment. This chapter includes add
itional
information on hardware configuration, installation and preparation for operation of the
SIWAREX WP321.
The safety notes must be observed.
Note
The device was developed, manufactured, tested and documented in compliance with the
relevant safety standards. The device does usually not pose any risks of material damage or
personal injury.

Safety notes
2.2 IT Security
SIWAREX WP321
12 Manual, 07/2014, A5E33715669A-02
2.2
IT Security
Siemens provides automation and drive products with industrial security functions that
support the secure operation of plants or machines. They are an important component in a
holistic industrial security concept. With this in mind, our products undergo continuous
development. We therefore recommend that you keep yourself informed with respect to our
product updates. Detailed technical information can be found at:
http://support.automation.siemens.com (http://www.siemens.de/automation/csi_en_WW).
To ensure the secure operation of a plant or machine it is also necessary to take suitable
preventive action (e.g. cell protection concept) and to integrate the automation and drive
components into a state-of-the-art holistic industrial security concept for the entire plant or
machine. Products used from other manufacturers should also be taken into account here.
You will find further information under:
http://www.siemens.com/industrialsecurity (http://www.siemens.com/industrialsecurity).

SIWAREX WP321
Manual, 07/2014, A5E33715669A-02 13
Description
3
3.1
Product overview
SIWAREX WP321 is a versatile and flexible weighing module that can be operated as a
static weighing instrument.
The electronic weighing system can be used in SIMATIC ET 200SP and uses all features of
a modern automation system, such as integrated communication, operation and monitoring,
the diagnostics system as well as the configuration tools in the TIA Portal or SIMATIC Step7
and WinCC flexible.
3.2
Area of application
The electronic weighing system described here is the perfect solution for applications in
which signals from weighing or force sensors are acquired and processed. The
SIWAREX WP321 is a very accurate electronic weighing system.
It can be used in almost all industrial weighing applications not requiring official calibration.
Use in potentially explosive atmospheres (with Ex interface SIWAREX IS) it's also possible.
3.3
System integration in SIMATIC
The electronic weighing system described here is a technology module for
SIMATIC ET 200SP. It can be used as desired in the configuration of the automation
solution, including the weighing application. You can create optimal solutions for small and
medium-sized plants by combining the suitable SIMATIC modules. You can create
customized or industry-specific solutions in no time with the help of the configuration
package available under the "Ready for use" application for SIMATIC.
Solutions are possible with S7-300, S7-1200 as well as S7-1500 CPUs. TIA Portal or Step 7
Classic can be used as the configuration software.

Description
3.3 System integration in SIMATIC
SIWAREX WP321
14 Manual, 07/2014, A5E33715669A-02
Figure 3-1 System overview

Description
3.4 Customer benefits
SIWAREX WP321
Manual, 07/2014, A5E33715669A-02 15
3.4
Customer benefits
The electronic weighing system described here is characterized by decisive advantages:
●Uniform design technology and consistent communication in SIMATIC ET 200SP
●Parameter assignment by means of an operator panel, STEP7 user program or PC
●Uniform configuration option in the SIMATIC TIA Portal or SIMATIC Step7
●Measuring of weight with a resolution of up to +/- 2 million parts
●High accuracy 0.05%
●High measuring rate of 100 Hz
●Limit monitoring
●Flexible adaptation to varying requirements
●Easy adjustment of the scale using the SIWATOOL program
●Automatic calibration is possible without the need for calibration weights
●Module replacement is possible without recalibrating the scale
●Use in Ex Zone 2 / ATEX approval
●Intrinsically safe load cell supply for Ex Zone 1 (SIWAREX IS option)
●Diagnostics functions

Description
3.5 Scope of delivery
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16 Manual, 07/2014, A5E33715669A-02
3.5
Scope of delivery
The scope of supply consists of the SIWAREX WP321 weighing module. Required
accessories → Accessories (Page 115)
Note
The SIWAREX WP321 configuration package is required for configuration of the
SIWAREX WP321 electronic weighing system → Accessories (Page 115). The configuration
package is not included in the scope of delivery of the module.

SIWAREX WP321
Manual, 07/2014, A5E33715669A-02 17
Application planning
4
4.1
Functions
The primary task of the electronic weighing system is the measurement and registration of
the current weight value. The integration in SIMATIC gives you the option to process the
weight value directly in the PLC (
P
rogrammabel
L
ogic
C
ontroller).
The SIWAREX WP321 is calibrated at the factory. This allows for automatic calibration of the
scale without the need for calibration weights and replacement of modules without the need
for recalibrating the scale.
A PC for setting the parameters of the electronic weighing system can be connected via the
RS485 interface.
The SIWAREX WP321 electronic weighing system can also be used in potentially explosive
atmospheres (Zone 2). The load cells are supplied intrinsically safe in Zone 1 applications
when you use the optional Ex interface SIWAREX IS.

Application planning
4.2 Parameter assignment options
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18 Manual, 07/2014, A5E33715669A-02
4.2
Parameter assignment options
4.2.1
Parameter assignment with the PC
You can set the scale parameters with the convenience of the familiar Windows interface by
using the "SIWATOOL" PC parameter assignment software.
You can use the program for commissioning the scale without any knowledge of automation
technology. When servicing is required, you can analyze and test the processes in the scale
independently of the automation system or Operator Panel with the help of the PC. You can
read out the diagnostic buffer from the SIWAREX module to assist you in the event analysis.
The figure below illustrates the structure of the individual program windows.
Figure 4-1 SIWATOOL overview
SIWATOOL does not only offer support when you set the scale but also when you analyze
the diagnostic buffer that can be saved after being read out of the module together with the
parameters. The display of the current scale status can be configured.
You can switch between several languages in the program.
You require an RS485/USB converter (see Accessories (Page 115)).
4.2.2
Parameter assignment with the SIMATIC Panel
SIWAREX WP321 parameters can be assigned using a SIMATIC Panel connected to the
SIMATIC CPU. The "Ready-for-use" application software is used for this.

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Mounting
5
5.1
Installation guideline
When assembling the SIMATIC components together with the electronic weighing system
described here, the setup, installation and wiring guidelines for the SIMATIC ET 200SP must
be observed (see system manual "SIMATIC ET 200SP, ET 200SP distributed I/O system",
order no.: A5E03576848).
This manual describes additional installation and wiring aspects specific to the electronic
weighing system.

Mounting
5.2 EMC-compliant setup
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20 Manual, 07/2014, A5E33715669A-02
5.2
EMC-compliant setup
5.2.1
Introduction
The electronic weighing system described here was developed for use in industrial
environments and complies with high EMC requirements. It ensures safe operation even in
harsh environmental conditions. Nevertheless, you should still carry out EMC planning
before installing your devices in order to determine any sources of interference and include
them in your considerations.
EMC
EMC (electromagnetic compatibility) describes the capability of electrical equipment to
operate without errors in a given electromagnetic environment, without being subject to
external influence and without influencing external devices in any way.
5.2.2
Possible effects of interference
Electromagnetic interferences can influence the electronic weighing system described here
in various ways:
●Electromagnetic fields having a direct influence on the system
●Interferences transported by communication cables
●Interferences having an effect via process cables
●Interferences entering the system via the power supply and/or protective ground
Interferences can impair the fault-free functioning of the electronic weighing system.
5.2.3
Coupling mechanisms
Depending on the propagation medium (conducted or non-conducted) and the distance
between the interference source and the device, interferences can enter the faulty device
through four different coupling mechanisms:
●Electrical coupling
●Capacitive coupling
●Inductive coupling
●Radiation coupling