Siemens SIWAREX WP251 User Manual
SIWAREX WP251
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Weighing systems
Electronic Weighing System SIWAREX WP251
Manual
12/2015
A5E37203357A
Introduction
1
Safety notes
2
Description
3
Application planning
4
Mounting
5
Connection
6
Commissioning
7
Scale parameters and
functions
8
Errors and messages
9
Command lists
10
Communication with
SIMATIC S7-1200
11
Operation requiring official
calibration
12
Technical specifications
13
Accessory
14
ESD guidelines
A
List of abbreviations
B
Siemens AG
Division Process Industries and Drives
Postfach 48 48
90026 NÜRNBERG
GERMANY
Document order number: A5E37203357A
Ⓟ
Copyright © Siemens AG 2015.
All rights reserved
Legal information
Warning notice system
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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.
Qualified Personnel
personnel qualified
Proper use of Siemens products
WARNING
Siemens products may only be used for the applications described in the catalog and in the relevant technical
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
Disclaimer of Liability
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.
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.
The product/system described in this documentation may be operated only by
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.
for the specific
Note the following:
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
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.
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.
12/2015 Subject to change
Table of contents
1 Introduction ........................................................................................................................................... 15
2 Safety notes .......................................................................................................................................... 17
3 Description ............................................................................................................................................ 19
4 Application planning .............................................................................................................................. 21
5 Mounting ............................................................................................................................................... 25
6 Connection ........................................................................................................................................... 29
1.1 Purpose of the manual ............................................................................................................ 15
1.2 Basic knowledge required ....................................................................................................... 15
1.3 Manual - range of validity ........................................................................................................ 15
1.4 Technical support .................................................................................................................... 15
2.1 General safety instructions ..................................................................................................... 17
2.2 Security messages .................................................................................................................. 17
3.1 Product overview .................................................................................................................... 19
3.2 Area of application .................................................................................................................. 19
3.3 System integration in SIMATIC ............................................................................................... 19
3.4 Scope of delivery .................................................................................................................... 20
4.1 Functions ................................................................................................................................ 21
4.2 Parameter assignment options ............................................................................................... 21
4.2.1 Parameter assignment with the PC ........................................................................................ 21
4.2.2 Parameter assignment with a SIMATIC Panel ....................................................................... 22
4.2.3 Parameter assignment by means of the Modbus interface .................................................... 23
5.1 Installation guideline ............................................................................................................... 25
5.2 EMC-compliant installation ..................................................................................................... 25
5.2.1 Introduction ............................................................................................................................. 25
5.2.2 Possible effects of interference ............................................................................................... 25
5.2.3 Coupling mechanisms............................................................................................................. 26
5.2.4 Five basic rules for securing EMC .......................................................................................... 26
5.3 Mounting on the SIMATIC S7-1200 ........................................................................................ 27
6.1 Overview ................................................................................................................................. 29
6.2 24 V connection ...................................................................................................................... 30
6.3 Connecting the load cells ........................................................................................................ 30
6.4 Shield connection .................................................................................................................... 31
6.5 Connection of digital outputs (4 x DQ) .................................................................................... 34
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7 Commissioning ..................................................................................................................................... 41
8 Scale parameters and functions ............................................................................................................ 57
6.6 Connection of digital inputs (4 x DI) ....................................................................................... 35
6.7 Connection of the analog output (1 x AQ) ............................................................................. 36
6.8 Connection of RS485 serial interface .................................................................................... 36
6.9 Connection of Siebert display via RS485 .............................................................................. 37
6.10 Connection of the Ethernet interface ..................................................................................... 38
6.11 Activation of write protection .................................................................................................. 38
6.12 Attachment of calibration protection plate .............................................................................. 39
7.1 Introduction ............................................................................................................................ 41
7.2 Factory setting of the mode selector ...................................................................................... 41
7.3 Automatic quick calibration with SIWATOOL ......................................................................... 42
7.3.1 Overview ................................................................................................................................ 42
7.3.2 Activate service mode ............................................................................................................ 43
7.3.3 Load standard parameters ..................................................................................................... 43
7.3.4 Input of required parameters .................................................................................................. 44
7.3.5 Complete automatic calibration .............................................................................................. 45
7.3.6 Receive all data...................................................................................................................... 45
7.3.7 Checking the scale after calibration ....................................................................................... 45
7.4 Quick calibration with calibration weights and SIWATOOL ................................................... 46
7.4.1 Introduction ............................................................................................................................ 46
7.4.2 Activate service mode ............................................................................................................ 46
7.4.3 Load standard parameters ..................................................................................................... 46
7.4.4 Input of required parameters .................................................................................................. 46
7.4.5 Calibration .............................................................................................................................. 47
7.4.6 Receive all data...................................................................................................................... 48
7.4.7 Checking the scale following calibration ................................................................................ 48
7.5 Service with the SIWATOOL program ................................................................................... 48
7.5.1 General .................................................................................................................................. 48
7.5.2 Windows and functions of SIWATOOL .................................................................................. 49
7.5.3 Offline parameter assignment ................................................................................................ 50
7.5.4 IP address for SIWAREX ....................................................................................................... 50
7.5.4.1 Introduction ............................................................................................................................ 50
7.5.4.2 E
ntering a known SIWAREX IP address ............................................................................... 51
7.5.4.3 Determining an unknown IP address ..................................................................................... 51
7.5.4.4 Setting up a network .............................................................................................................. 51
7.5.5 Online parameter assignment ................................................................................................ 51
7.5.6 Entering parameters with SIWATOOL ................................................................................... 52
7.5.7 Recording scale traces .......................................................................................................... 52
7.5.8 Firmware update .................................................................................................................... 53
7.5.9 Reading out the saved scale logs .......................................................................................... 55
8.1 Parameters and functions ...................................................................................................... 57
8.2 Weighing steps....................................................................................................................... 58
8.2.1 Introduction ............................................................................................................................ 58
8.2.2 Operating mode NAWI (non-automatic weighing instrument) - Filling ................................... 58
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8.2.3 Operating mode NAWI (non-automatic weighing instrument) - Removal ............................... 59
8.2.4 Operating mode AWI (automatic weighing instruments) ........................................................ 59
8.2.5 Operating mode ACI (automatic catchweighing instruments) - Filling .................................... 60
8.2.6 Operating mode ACI (automatic catchweighing instruments) - Removal ............................... 61
8.3 DR 3 Calibration parameters .................................................................................................. 61
8.3.1 Overview ................................................................................................................................. 61
8.3.2 Scale name ............................................................................................................................. 66
8.3.3 Unit of weight .......................................................................................................................... 66
8.3.4 Gross identifier ........................................................................................................................ 66
8.3.5 Code for regulations................................................................................................................ 67
8.3.6 Minimum weighing range ........................................................................................................ 67
8.3.7 Maximum weighing range ....................................................................................................... 67
8.3.8 Calibration weights 0, 1, 2 and calibration digits 0, 1, 2 ......................................................... 67
8.3.9 Scale interval .......................................................................................................................... 68
8.3.10 Zero by power-on .................................................................................................................... 68
8.3.11 Zero by power-on when tare ≠ 0 ............................................................................................. 68
8.3.12 Automatic zero adjustment ..................................................................................................... 68
8.3.13 Subtractive / additive tare device ............................................................................................ 69
8.3.14 Weight simulation allowed ...................................................................................................... 69
8.3.15 Automatic zero tracking .......................................................................................................... 69
8.3.16 Maximum tare load ................................................................................................................. 70
8.3.17 Maximum negative zero setting limit (power-on) .................................................................... 70
8.3.18 Maximum positive zero setting limit (power-on) .....................................................................
8.
3.19 Maximum negative zero setting limit (semi-automatically) ..................................................... 70
70
8.3.20 Maximum positive zero setting limit (semi-automatically) ....................................................... 71
8.3.21 Standstill monitoring ................................................................................................................ 71
8.3.22 Standstill 1 - range .................................................................................................................. 72
8.3.23 Standstill 1 - time .................................................................................................................... 72
8.3.24 Max. waiting time for standstill 1 ............................................................................................. 72
8.3.25 Standstill 2 - range .................................................................................................................. 73
8.3.26 Standstill 2 - time .................................................................................................................... 73
8.3.27 Setting time before standstill 2 ................................................................................................ 73
8.3.28 Frequency low pass filter 1 ..................................................................................................... 74
8.3.29 Order no. low pass filter 1 ....................................................................................................... 74
8.3.30 Depth average filter ................................................................................................................. 74
8.3.31 Weighing operating mode ....................................................................................................... 75
8.3.32 SecureDisplay including weighing range data ........................................................................ 75
8.3.33 SecureDisplay interface .......................................................................................................... 75
8.3.34 SecureDisplay version ............................................................................................................ 75
8.3.35 Smallest zoom factor of SecureDisplay .................................................................................. 75
8.3.36 Grid frequency ........................................................................................................................ 75
8.4 Calibration ............................................................................................................................... 76
8.4.1 Calibration with calibration weights ......................................................................................... 76
8.4.2 Automatic calibration............................................................................................................... 78
8.5 DR 4 Output of calculated calibration digits ............................................................................
8.
5.1 Overview ................................................................................................................................. 79
5.2 Calibration digits 0, 1, 2 (calculated) ....................................................................................... 80
8.
8.6 DR 5 Tare / zero memory ....................................................................................................... 80
8.6.1 Overview ................................................................................................................................. 80
8.6.2 Effective tare weight - from specification 1, 2 or 3 .................................................................. 81
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8.6.3 Effective tare weight (semi-automatic) ................................................................................... 81
8.6.4 Zero by power-on (value when switching on) ........................................................................ 82
8.6.5 Zero weight (semi-automatic) ................................................................................................ 82
8.6.6 Current zero tracking weight .................................................................................................. 82
8.6.7 Dead load ............................................................................................................................... 82
8.7 DR 6 Limits ............................................................................................................................. 82
8.7.1 Overview ................................................................................................................................ 82
8.7.2 Limit value 1 ON, limit value 2 ON, limit value 1 OFF, limit value 2 OFF .............................. 84
8.7.3 Switch-on delay limit 3 (empty) .............................................................................................. 85
8.7.4 Limit 3 - empty ........................................................................................................................ 85
8.8 DR 7 Process interfaces ........................................................................................................ 86
8.8.1 Overview ................................................................................................................................ 86
8.8.2 Assignment of digital input DI.0, DI.1, DI.2, DI.3 ................................................................... 90
8.8.3 Input filtering (hardware setting) ............................................................................................ 91
8.8.4 Assignment of digital output DQ.0, DQ.1, DQ.2, DQ.3 .......................................................... 91
8.8.5 Response of digital outputs to faults or SIMATIC STOP ....................................................... 92
8.8.6 Substitute value for DQ 0, 1, 2, 3 following fault or SIMATIC STOP ..................................... 92
8.8.7 Analog output range ............................................................................................................... 93
8.8.8 Analog output source ............................................................................................................. 93
8.8.9 Response of analog output to faults or SIMATIC STOP........................................................ 93
8.8.10 Start value for the analog output ............................................................................................ 93
8.8.11 End value for the analog output ............................................................................................. 93
8.8.12 Output value following fault or SIMATIC STOP ..................................................................... 94
8.8.13 Trace recording cycle .............................................................................................................
8.14 Trace storage method ............................................................................................................ 94
8.
94
8.9 DR 8 date and time ................................................................................................................ 95
8.10 DR 9 module information ....................................................................................................... 95
8.11 DR 10 Load cell parameters .................................................................................................. 96
8.11.1 Overview ................................................................................................................................ 96
8.11.2 Number of support points ....................................................................................................... 97
8.11.3 Load cell characteristic value ................................................................................................. 98
8.11.4 Rated load of a load cell ........................................................................................................ 98
8.12 DR 12 Ethernet parameters ................................................................................................... 98
8.12.1 Overview ................................................................................................................................ 98
8.12.2 Device MAC address ............................................................................................................. 99
8.12.3 Port MAC address .................................................................................................................. 99
8.12.4 IP address .............................................................................................................................. 99
8.12.5 Subnet mask ........................................................................................................................ 100
8.12.6 Gateway ............................................................................................................................... 100
8.12.7 Device name ........................................................................................................................ 100
8.13 DR 13 RS485 parameters .................................................................................................... 100
8.13.1 Overview .............................................................................................................................. 100
8.13.2 RS485 protocol .................................................................................................................... 102
8.13.3 RS485 baud rate .................................................................................................................. 102
8.13.4 RS485 character parity ........................................................................................................ 102
8.13.5 RS485 number of data bits .................................................................................................. 102
8.13.6 RS485 number of stop bits .................................................................................................. 103
8.13.7 RS485 Modbus address ......................................................................................................
13.8 Decimal place for Siebert indicator ...................................................................................... 103
8.
103
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8.14 DR 14 Selection process value 1, 2 ...................................................................................... 103
8.15 DR 15 Preset tare ................................................................................................................. 104
8.15.1 Overview ............................................................................................................................... 104
8.15.2 Preset tare weight 1 .............................................................................................................. 105
8.16 DR 16 Weight simulation ...................................................................................................... 105
8.16.1 Overview ............................................................................................................................... 105
8.16.2 Weight simulation specification ............................................................................................. 106
8.17 DR 17 Control analogue output ............................................................................................ 106
8.17.1 Overview ............................................................................................................................... 106
8.17.2 Analog output specification ................................................................................................... 106
8.18 DR18 Control digital outputs ................................................................................................. 107
8.18.1 Overview ............................................................................................................................... 107
8.18.2 Specification for digital outputs DQ.0, DQ.1, DQ.2, DQ.3 .................................................... 108
8.18.3 Transitions for weighing steps 0 to 7 .................................................................................... 108
8.19 DR 20 Single set point .......................................................................................................... 109
8.19.1 Overview ............................................................................................................................... 109
8.19.2 Single set point ..................................................................................................................... 109
8.20 DR 21 Total set point ............................................................................................................ 110
8.20.1 Overview ............................................................................................................................... 110
8.20.2 Total set point ....................................................................................................................... 110
8.21 DR 22 Tolerance parameters ............................................................................................... 111
8.21.1 Overview ............................................................................................................................... 111
8.21.2 Parameter relation ................................................................................................................ 115
8.21.3 Tolerance limit TH2 ...............................................................................................................
21.4 Tolerance limit TH1 ............................................................................................................... 116
8.
116
8.21.5 Tolerance limit TL1 ............................................................................................................... 116
8.21.6 Tolerance limit TL2 ............................................................................................................... 116
8.21.7 Behavior in case of TH1 error ............................................................................................... 116
8.21.8 Behavior in case of TL1 error ............................................................................................... 116
8.21.9 Pulse duration for pulse post dosing ..................................................................................... 116
8.21.10 Number of not controlled weighings ..................................................................................... 117
8.21.11 Capture of weighings into statistics ...................................................................................... 117
8.22 DR 23 Material parameters ................................................................................................... 118
8.22.1 Overview ............................................................................................................................... 118
8.22.2 Parameter relation ................................................................................................................ 119
8.22.3 Fine weight ............................................................................................................................ 119
8.22.4 Trailing weight ....................................................................................................................... 119
8.22.5 Blocking time coarse signal .................................................................................................. 120
8.22.6 Blocking time fine signal ....................................................................................................... 120
8.22.7 Shut-off correction weight ..................................................................................................... 121
8.23 DR 24 Controller and filter parameters ................................................................................. 121
8.23.1 Overview ............................................................................................................................... 121
8.23.2 Parameter relation ................................................................................................................ 123
8.23.3 Type of controller .................................................................................................................. 123
8.23.4 Control factor of proportional controller ................................................................................
8.
23.5 Maximum corrective action ................................................................................................... 123
8.23.6 Controller deadband - upper limit ......................................................................................... 124
8.23.7 Controller deadband - lower limit ..........................................................................................
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8.23.8 Reaction when max. corrective action is exceeded ............................................................. 124
8.23.9 Selection for dosing filter ...................................................................................................... 124
8.23.10 Frequency low pass filter 2 .................................................................................................. 125
8.23.11 Order no. low pass filter 2 .................................................................................................... 125
8.23.12 Depth average filter .............................................................................................................. 126
8.23.13 Adopt corrected fine/trailing value to DR 23 automatically .................................................. 126
8.24 DR 25 Dosing device parameters ........................................................................................ 126
8.24.1 Overview .............................................................................................................................. 126
8.24.2 Maximum single set point .................................................................................................... 128
8.24.3 "Coarse" set value for analogue output ............................................................................... 128
8.24.4 "Fine" set value for analogue output .................................................................................... 129
8.24.5 Minimum automatic tare weight ........................................................................................... 129
8.24.6 Maximum automatic tare weight .......................................................................................... 129
8.24.7 Maximum weighing time ...................................................................................................... 129
8.24.8 Weighing start options ......................................................................................................... 130
8.24.9 Cycle time for automatic zero setting ................................................................................... 130
8.24.10 Number of weighings without automatic taring/zero setting ................................................ 130
8.24.11 Check stop ........................................................................................................................... 130
8.24.12 Automatic emptying ............................................................................................................. 131
8.24.13 Emptying time ...................................................................................................................... 131
8.24.14 Maximum emptying time ...................................................................................................... 131
8.25 DR 28 Additional strings for log ........................................................................................... 132
8.25.1 Overview .............................................................................................................................. 132
8.25.2 Strings 1, 2, 3 and 4 .............................................................................................................
25.3 Sting selection for automatic logging ................................................................................... 133
8.
132
8.26 DR 29 Configuration of technology messages .................................................................... 133
8.27 DR 30 Process state ............................................................................................................ 135
8.27.1 Overview .............................................................................................................................. 135
8.27.2 Gross, net and tare process values ..................................................................................... 140
8.27.3 Gross, net and tare weights ................................................................................................. 140
8.27.4 Gross/Net weight x10 ........................................................................................................... 140
8.27.5 Gross/Net process weight 2 ................................................................................................. 140
8.27.6 Refresh counter.................................................................................................................... 140
8.27.7 Actual weight of last dosing ................................................................................................. 140
8.27.8 Totalizer 1 and Totalizer 2 ................................................................................................... 140
8.27.9 Youngest protocol-ID ........................................................................................................... 141
8.27.10 Date & time .......................................................................................................................... 141
8.27.11 Current weighing step .......................................................................................................... 141
8.28 DR 31 Process state extended ............................................................................................ 141
8.28.1 Overview .............................................................................................................................. 141
8.28.2 Unfiltered digit value ............................................................................................................ 143
8.28.3 Digits filtered by F1 .............................................................................................................. 143
8.28.4 Filtered digit value 2 ............................................................................................................. 143
8.28.5 Current analog output (mA) ................................................................................................. 144
8.28.6 Current analog output (digits) ..............................................................................................
28.7 Current status digital input DI.0, DI.1, DI.2 and DI.3 ............................................................ 144
8.
144
8.28.8 DIP switch 1 and 2 ............................................................................................................... 144
8.28.9 Current status digital output DQ.0, DQ.1, DQ.2 and DQ.3 ..................................................
28.10 Refresh counter.................................................................................................................... 144
8.
144
8.28.11 Current load cell signal in mV .............................................................................................. 145
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9 Errors and messages .......................................................................................................................... 163
10 Command lists .................................................................................................................................... 179
8.28.12 Current fine weight ................................................................................................................ 145
8.28.13 Current trailing weight ........................................................................................................... 145
8.28.14 Tolerance limits TH2, TH1, TL1 and TL2.............................................................................. 145
8.29 DR 32 Error messages ......................................................................................................... 145
8.29.1 Overview ............................................................................................................................... 145
8.29.2 Operating errors, technology messages, data/command errors .......................................... 150
8.30 DR 34 ASCII weight display .................................................................................................. 150
8.30.1 Overview ............................................................................................................................... 150
8.30.2 Content of the display string ................................................................................................. 150
8.31 DR 35 SecureDisplay data ................................................................................................... 151
8.32 DR 38 Min/max pointer ......................................................................................................... 152
8.33 DR 39 Statistics .................................................................................................................... 152
8.34 DR 41/42 Data memory ........................................................................................................ 154
8.35 DR 45 Protocol request......................................................................................................... 155
8.35.1 Overview ............................................................................................................................... 155
8.35.2 Protocol ID to be read ........................................................................................................... 156
8.36 DR 46 Protocol content ......................................................................................................... 157
8.36.1 Overview ............................................................................................................................... 157
8.36.2 Oldest report ID ..................................................................................................................... 158
8.36.3 Newest report ID ................................................................................................................... 158
8.36.4 Selected protocol-ID ............................................................................................................. 158
8.36.5 Protocol ................................................................................................................................. 158
8.36.6 Date, time .............................................................................................................................. 159
8.
37 DR 47 Logbook ..................................................................................................................... 159
8.38 DR 48 date and time 2 (for Modbus) .................................................................................... 160
9.1 Message and error types ...................................................................................................... 163
9.2 Message paths ...................................................................................................................... 163
9.3 Evaluating errors/messages with the help of SIWATOOL .................................................... 164
9.4 Evaluating errors/messages with the help of the function block ........................................... 164
9.5 Evaluating errors/messages using Modbus .......................................................................... 164
9.6 Operating errors .................................................................................................................... 164
9.6.1 Operating errors .................................................................................................................... 164
9.6.2 Technology messages .......................................................................................................... 165
9.6.3 Data and command errors .................................................................................................... 167
9.6.4 Data and command errors - Additional information .............................................................. 172
9.6.5 Messages by LEDs on the module ....................................................................................... 177
10.1 Overview ............................................................................................................................... 179
10.2 Command lists ...................................................................................................................... 179
10.3 Command groups of the SIWAREX WP251 ......................................................................... 184
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11 Communication with SIMATIC S7-1200 ............................................................................................... 185
12 Operation requiring official calibration ................................................................................................... 197
13 Technical specifications ....................................................................................................................... 203
14 Accessory ............................................................................................................................................ 213
A ESD guidelines .................................................................................................................................... 215
B List of abbreviations ............................................................................................................................. 217
Index ................................................................................................................................................... 219
Tables
11.1 Integration in SIMATIC S7-1200 .......................................................................................... 185
11.1.1 General information ............................................................................................................. 185
11.1.2 Creating the hardware configuration .................................................................................... 186
11.1.3 Calling of function block ....................................................................................................... 188
11.1.4 Working with the function block ........................................................................................... 189
11.1.5 I/O interface of function block .............................................................................................. 191
11.1.6 Error codes of function block ............................................................................................... 192
11.2 Communication via Modbus ................................................................................................. 193
11.2.1 Introduction .......................................................................................................................... 193
11.2.2 Principle of data transmission .............................................................................................. 193
11.2.3 Data record concept ............................................................................................................. 194
11.2.4 Command mailboxes ........................................................................................................... 195
11.2.5 Reading registers ................................................................................................................. 195
11.2.6 Writing registers ................................................................................................................... 196
12.1 Preparing for calibration ....................................................................................................... 197
12.1.1 Calibration set ...................................................................................................................... 197
12.1.2 Scale design ......................................................................................................................... 197
12.1.3 Installation and parameter assignment of the calibratable SecureDisplay main display
in the HMI ............................................................................................................................. 197
12.1.4 Parameterization of the scale .............................................................................................. 198
12.1.5 Adjustment and preliminary checking of the scale ............................................................... 198
12.1.6 Calibration label ................................................................................................................... 198
12.2 Verification ........................................................................................................................... 198
12.2.1 Checking of parameters relevant to the verification............................................................. 198
12.2.2 Checking of parameters relevant to the device ................................................................... 200
13.1 Technical specifications ....................................................................................................... 203
13.2 Electrical, EMC and climatic requirements .......................................................................... 207
13.3 Approvals ............................................................................................................................. 211
A.1 ESD Guidelines .................................................................................................................... 215
B.1 List of abbreviations ............................................................................................................. 217
Table 6- 1 Connection of the 24 V supply ..................................................................................................... 30
Table 6- 2 Load cell connections on the module ........................................................................................... 31
Table 6- 3 Connection of the digital outputs .................................................................................................. 35
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Table 6- 4 Connection of the digital inputs .................................................................................................... 35
Table 6- 5 Connection of analog output ........................................................................................................ 36
Table 6- 6 Connection of RS485 serial interface .......................................................................................... 36
Table 6- 7 Settings of Siebert display S102 .................................................................................................. 37
Table 6- 8 Activation of write protection ........................................................................................................ 38
Table 8- 1 Assignment of data record 3 ........................................................................................................ 62
Table 8- 2 Assignment of data record 4 ........................................................................................................ 79
Table 8- 3 Assignment of data record 5 ........................................................................................................ 80
Table 8- 4 Assignment of data record 6 ........................................................................................................ 82
Table 8- 5 Assignment of data record 7 ........................................................................................................ 86
Table 8- 6 Bit 0 defines digital output 0 (DQ 0) ............................................................................................. 92
Table 8- 7 Bit 1 defines digital output 2 (DQ 2) ............................................................................................. 92
Table 8- 8 Assignment of data record 8 ........................................................................................................ 95
Table 8- 9 Assignment of data record 9 ........................................................................................................ 95
Table 8- 10 Assignment of data record 10 ...................................................................................................... 96
Table 8- 11 Assignment of data record 12 ...................................................................................................... 98
Table 8- 12 Assignment of data record 13 .................................................................................................... 100
Table 8- 13 Selection table for process value 1,2 ......................................................................................... 103
able 8- 14 Structure of status of analog output, digital outputs, and digital inputs ..................................... 104
T
Table 8- 15 Assignment of data record 15 .................................................................................................... 104
Table 8- 16 Assignment of data record 16 .................................................................................................... 105
Table 8- 17 Assignment of data record 17 .................................................................................................... 106
Table 8- 18 Assignment of data record 18 .................................................................................................... 107
Table 8- 19 Assignment of data record 20 .................................................................................................... 109
Table 8- 20 Assignment of data record 21 .................................................................................................... 110
Table 8- 21 Assignment of data record 22 .................................................................................................... 111
Table 8- 22 Assignment of data record 23 .................................................................................................... 118
Table 8- 23 Assignment of data record 24 .................................................................................................... 121
Table 8- 24 Assignment of data record 25 .................................................................................................... 126
Table 8- 25 Assignment of data record 28 .................................................................................................... 132
Table 8- 26 Assignment of data record 29 .................................................................................................... 133
Table 8- 27 Assignment of data record 30 .................................................................................................... 136
Table 8- 28 Assignment of data record 31 .................................................................................................... 141
Table 8- 29 Assignment of data record 32 .................................................................................................... 146
Table 8- 30 Assignment of data record 34 .................................................................................................... 150
Table 8- 31 Assignment of data record 35 .................................................................................................... 151
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Table of contents
Table 8- 32 Assignment of data record 38 .................................................................................................... 152
Table 8- 33 Assignment of data record 39 .................................................................................................... 152
Table 8- 34 Assignment of data record 41 .................................................................................................... 154
Table 8- 35 Assignment of data record 42 .................................................................................................... 155
Table 8- 36 Assignment of data record 45 .................................................................................................... 155
Table 8- 37 Assignment of data record 46 .................................................................................................... 157
Table 8- 38 Assignment of data record 47 .................................................................................................... 159
Table 8- 39 Assignment of data record 48 .................................................................................................... 160
Table 9- 1 Technology messages ............................................................................................................... 165
Table 9- 2 Data and command errors ......................................................................................................... 167
Table 10- 1 Service commands ..................................................................................................................... 180
Table 10- 2 Protocol commands, statistics, logbook ..................................................................................... 181
Table 10- 3 Trace commands ....................................................................................................................... 181
Table 10- 4 Display changeover for DR 34 and SecureDisplay .................................................................... 181
Table 10- 5 Scale commands ........................................................................................................................ 183
Table 10- 6 Scale commands ........................................................................................................................ 183
Table 10- 7 Command groups of the SIWAREX WP251 .............................................................................. 184
Table 11- 1 Memory requirements of the function block ...............................................................................
185
Table 11- 2 Statuses/errors when working with the function block ............................................................... 192
Table 11- 3 Command mailbox 1: Highest priority ........................................................................................ 195
Table 11- 4 Command mailbox 2: Average priority ....................................................................................... 195
Table 11- 5 Command mailbox 3: Low priority .............................................................................................. 195
Table 13- 1 Technical specifications: 24 V power supply ............................................................................. 203
Table 13- 2 Technical specifications: Power supply from SIMATIC S7 backplane bus ................................ 203
Table 13- 3 Technical specifications: Analog load cell interface connection ................................................ 203
Table 13- 4 Technical specifications: ............................................................................................................ 204
Table 13- 5 Technical specifications: Digital outputs .................................................................................... 205
Table 13- 6 Technical specifications: Digital inputs ...................................................................................... 205
Table 13- 7 Technical specifications: Real-time clock .................................................................................. 206
Table 13- 8 Technical specifications: RS485 interface ................................................................................. 206
Table 13- 9 Technical specifications: Ethernet ............................................................................................. 206
Table 13- 10 Technical specifications: ............................................................................................................ 206
Table 13- 11 Technical specifications: Mechanical requirements and data .................................................... 207
Table 13- 12 Requirements: Electrical protection and safety requirements ................................................... 207
Table 13- 13 Requirements: Interference emission in industrial area in accordance with EN 61000-6-4 ...... 208
Table 13- 14 Requirements: Interference immunity in industrial area in accordance with EN 61000-6-2 ...... 209
SIWAREX WP251
12 Manual, 12/2015, A5E37203357A
Table of contents
Images
Table 13- 15 Operating conditions in accordance with IEC 60721 ................................................................. 210
Table 13- 16 Climatic requirements ................................................................................................................ 210
Image 3-1 System overview .......................................................................................................................... 20
Image 4-1 SIWATOOL overview ................................................................................................................... 22
Image 4-2 SIWAREX WP251 in stand-alone operation ................................................................................ 23
Image 6-1 SIWAREX WP251 connection areas ........................................................................................... 29
Image 6-2 Shielding in the screw gland ........................................................................................................ 31
Image 6-3 Installation of the shield connection element (example) .............................................................. 32
Image 6-4 Connection of strain gauge load cell with 4-wire system ............................................................. 33
Image 6-5 Connection of strain gauge load cell with 6-wire system ............................................................. 34
Image 6-6 Connection of Siebert display S102 ............................................................................................. 37
Image 6-7 Attachment of the calibration protection plates ............................................................................ 39
Image 7-1 Mode switch ................................................................................................................................. 41
Image 7-2 Quick calibration with marked parameters ................................................................................... 43
Image 7-3 Sending/receiving a data record / in SIWATOOL V7 ................................................................... 44
Image 7-4 Sending/receiving a data record / in SIWATOOL V7 ................................................................... 47
Image 7-5 Layout of the SIWATOOL user interface ..................................................................................... 49
Image 7-6 Sending/receiving a data record in SIWATOOL V7 ..................................................................... 50
Image 7-7 Trace export ................................................................................................................................. 53
Image 7-8 Downloading the firmware with SIWATOOL ................................................................................ 55
Image 8-1 Standstill monitoring ..................................................................................................................... 72
Image 8-2 Step response of digital low pass filter at f = 2 Hz .......................................................................
74
Image 8-3 Calibration digits and calibration weight ...................................................................................... 77
Image 8-4 Linearizing the scales' characteristic curve.................................................................................. 78
Image 8-5 Limit value configuration .............................................................................................................. 85
Image 8-6 Trailing weight ............................................................................................................................ 120
Image 8-7 Step response of digital low pass filter at f = 2 Hz ..................................................................... 125
Image 11-1 Configuring in the TIA Portal ...................................................................................................... 186
Image 11-2 Configuring with S7 .................................................................................................................... 186
Image 11-3 Start address of the module ....................................................................................................... 187
Image 11-4 Hardware identifier ..................................................................................................................... 187
Image 11-5 Block WP251PR......................................................................................................................... 188
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Table of contents
Image 11-6 CMD command mailboxes ......................................................................................................... 189
Image 11-7 s_IO_DATA................................................................................................................................. 191
Image 13-1 Current ranges for signal level according to Namur recommendation NE43 ............................ 205
Image A-1 Electrostatic voltages which an operator can be subjected to ................................................... 216
SIWAREX WP251
14 Manual, 12/2015, A5E37203357A
Introduction
1
1.1
Purpose of the manual
1.2
Basic knowledge required
1.3
Manual - range of validity
Type designation
Order No.
as of version
Note
This manual contains a description of all electronic weighing systems available at the date of
publication. We reserve th
on the module.
1.4
Technical support
Technical Support
This manual contains all the information required for assembling installing, wiring and
commissioning the SIWAREX WP251 electronic weighing system.
This manual requires basic knowledge of weighing technology. When used in the
SIMATIC S7-1200, basic knowledge of the SIMATIC S7-1200 automation system and the
TIA Portal are required.
This manual is valid for:
SIWAREX WP251 7MH4960-6AA01 HW: FS 3 FW: V.1.0.0
e right to include a Product Information with the latest information
SIWAREX WP251
Manual, 12/2015, A5E37203357A
You can contact Technical Support for weighing technology:
● E-mail (mailto:support.automation@siemens.com
● Phone: +49 (721) 595-2811
)
15
Introduction
Support Request:
Service & Support on the Internet
Additional Support
1.4 Technical support
You can contact Technical Support for S7-1200 products:
● Via the Internet using the
E-mail Weighing Technology (mailto:hotline.siwarex@siemens.com)
● By phone: +49 (911) 895-7222
● By fax: +49 (911) 895-7223
Additional information about our technical support is available on the Internet at
Support request (http://www.siemens.de/automation/support-request
In addition to our documentation, we offer a comprehensive knowledge base online on the
Internet at:
Technical support (http://www.siemens.de/automation/csi/service
There you will find:
● The latest product information, FAQs, downloads, tips and tricks.
● Our newsletter, providing you with the latest information about your products.
● A Knowledge Manager to find the right documents for you.
● Our bulletin board, where users and specialists share their knowledge worldwide.
● You can find your local contact partner for Industry Automation and Drives Technologies
in our partner database.
)
)
● Information about field service, repairs, spare parts and lots more under "Services".
Please contact your local Siemens representative and offices if you have any questions
about the products described in this manual and do not find the right answers.
Find your contact partner at:
Partner (http://www.automation.siemens.com/partner
A signpost to the documentation of the various products and systems is available at:
Documentation
(https://support.industry.siemens.com/cs/products?dtp=Manual&pnid=17781&lc=en-WW
)
)
SIWAREX WP251
16 Manual, 12/2015, A5E37203357A
Safety notes
2
2.1
General safety instructions
WARNING
WARNING
Note
The specifications o
installation and commissioning in the SIMATIC environment. This section provides additional
information on hardware configuration, installation and preparation for operation of the
SIWARE
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.
2.2
Security messages
Handling of the device/system by persons other than qualified personnel or ignoring the
warning instructions can result in severe injuries or damages. This means only qualified
personnel are permitted to handle this device/system.
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.
f the manual for the SIMATIC S7-1200 system apply for configuration,
X WP251.
SIWAREX WP251
Manual, 12/2015, A5E37203357A
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://www.siemens.de/automation/
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
).
17
Safety notes
2.2 Security messages
machine. Products used from other manufacturers should also be taken into account here.
You will find further information under:
(http://www.siemens.de/industrialsecurity
).
SIWAREX WP251
18 Manual, 12/2015, A5E37203357A
Description
3
3.1
Product overview
3.2
Area of application
3.3
System integration in SIMATIC
Note
The direct use of SIWAREX WP251 with fail
supported.
SIWAREX WP251 is a versatile and flexible weighing module that can be used for operation
as a non-automatic weighing instrument.
The electronic weighing system can be used in SIMATIC S7-1200 and uses all features of a
modern automation system, such as integrated communication, operator control and
monitoring, the diagnostic system as well as the configuration tools in the TIA Portal.
SIWAREX WP251 is the optimum solution wherever fast and precise dosing and filling are
required. The typical applications of SIWAREX WP251 are:
Automatic catchweighing instruments
●
Gravimetric filling instruments (AWI)
●
on-automatic weighing instrument (NAWI)
● N
● Weighing instruments in hazardous areas (with Ex interface SIWAREX IS)
The electronic weighing system described here is a technology module for SIMATIC S7-
1200. The system, including the weighing application, can be configured as desired in the
automation solution. 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.
SIWAREX WP251
Manual, 12/2015, A5E37203357A
-safe SIMATIC S7-1200 controllers is not yet
19
Description
3.4
Scope of delivery
Note
We recommend that you use the SIWAREX WP251 configuratio
the SIWAREX WP251 electronic weighing system. The configuration package is not included
in the product package of the module.
3.4 Scope of delivery
Image 3-1 System overview
SIWAREX WP251
20 Manual, 12/2015, A5E37203357A
The product package consists only of the SIWAREX WP251 weighing module.
n package for configuring
4
4.1
Functions
4.2
Parameter assignment options
4.2.1
Parameter assignment with the PC
SIWAREX WP251 controls complex dosing and filling processes completely autonomously.
The four digital outputs of the module can be used to directly control the dosing elements
(coarse and fine flow). Maximum accuracy is achieved since the weighing process is fully
independent of the CPU and its cycle time. The CPU can be used to manage recipes and
material parameters. These parameters and the desired set point are then transferred to
WP251 via a function block, and the dosing process is started. SIWAREX WP251
automatically optimizes the shut-off points, generates statistics, and logs every dosing
operation in the internal log memory, which is also accessible from the CPU and can be read
by the CPU. Various options are available for commissioning. The WP251 function block
enables full access to all parameters of the WP251. The free, downloadable example
application "Ready-for-use" enables complete commissioning, calibration and operation of
the scale from the touch panel - without any programming needed.
Furthermore, commissioning can be carried out with SIWATOOL V7, the PC service
software that communicates with the SIWAREX module via Ethernet. This enables access
via W-LAN when a WIFI access point is used. Remote access via the Internet is also
possible problem-free. Centralized access to all scales from a single location is possible for
servicing purposes – worldwide.
In addition, there is full access to all parameters and commands, both via the RS485 port
(Modbus RTU) and via the Ethernet interface (Modbus TCP/IP), meaning that full
commissioning and operation can also take place via these channels.
Stand-alone operation allows the module to be operated autonomously even without a
SIMATIC CPU. For this purpose, an HMI device can be connected directly to the Ethernet or
RS485 port of the WP251. The HMI device then communicates with the weighing module via
Modbus TCP/IP or RTU. This setup can also be selected to increase plant availability. If
WP251 is being operated with a SIMATIC S7-1200 and stand-alone operation is additionally
activated, WP251 can also continue operating (filling and dosing) without restrictions if the
CPU stops because a directly connected HMI device provides access to the module in this
situation.
The SIWAREX WP251 electronic weighing system can also be used in hazardous areas
(Zone 2). The load cells are supplied intrinsically safe in Zone 1 applications when you use
the optional Ex interface SIWAREX IS.
SIWAREX WP251
Manual, 12/2015, A5E37203357A
The scale parameters can be quickly assigned with the convenience of a Windows program
using the "SIWATOOL V7" PC parameter assignment software.
21
Application planning
4.2.2
Parameter assignment with a SIMATIC Panel
4.2 Parameter assignment options
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. Reading
the diagnostic buffer from the SIWAREX module is very helpful in analyzing events since the
last 100 error and operating messages with time stamp are saved in non-volatile memory.
The internal log memory can also be conveniently and easily read in .csv format using
SIWATOOL.
In addition, the tool can be used to create backup files, which can be re-imported into a new
module after module replacement in just a few a seconds – without the need for any
knowledge of the CPU program or automation environment.
SIWATOOL uses its own communication protocol, meaning that a connection to WP251 can
be established in parallel with the Modbus TCP/IP operation with SIWATOOL.
Image 4-1 SIWATOOL overview
SIWAREX WP251
22 Manual, 12/2015, A5E37203357A
All module parameters can be assigned and the module put into operation using a SIMATIC
HMI Panel connected to the S7-1200 CPU and the SIWAREX WP251 function and data
blocks.
Application planning
4.2.3
Parameter assignment by means of the Modbus interface
4.2 Parameter assignment options
The "Ready-for-Use" example application is included in the scope of delivery of the
configuration package and is also available from Siemens Online Support. In addition to the
function block, it contains a complete TIA HMI project for operation and commissioning of
scales, which the user can edit in TIA. Further information on integration in the TIA Portal
can be found in section Integration in SIMATIC S7-1200 (Page 185)
You have the option to assign the parameters with a SIMATIC panel which is connected
directly to the SIWAREX module. The SIWAREX module behaves like a Modbus slave in
this case. Loadable HMI software for a SIMATIC Panel TP700 Comfort is provided in the
scope of delivery of the configuration package.
All SIMATIC HMI Comfort Panels can be used for direct Modbus communication. The use of
SIMATIC HMI Basic Panels is not possible at the moment. A direct connection between a
SIMATIC HMI Panel and SIWAREX WP251 via Modbus RTU has not been approved.
The parameters for the SIWAREX module can also be prepared in a third-party system and
transmitted to the electronic weighing system by means of Modbus RTU or TCP/IP.
Image 4-2 SIWAREX WP251 in stand-alone operation
SIWAREX WP251
Manual, 12/2015, A5E37203357A
23
Application planning
4.2 Parameter assignment options
A detailed description of the assignment of the holding registers can be found in section
→ Scale parameters and functions (Page 57).
SIWAREX WP251
24 Manual, 12/2015, A5E37203357A
5
5.1
Installation guideline
5.2
EMC-compliant installation
5.2.1
Introduction
Overview
EMC
5.2.2
Possible effects of interference
When installing the SIMATIC components together with the electronic weighing system
described here, the setup, installation and wiring guidelines for the SIMATIC S7-1200 must
be observed (see system manual "SIMATIC S7 S7-1200 automation system", order no.:
A5E02486681).
This manual describes additional installation and wiring aspects specific to the electronic
weighing system.
The electronic weighing system described here was developed for use in industrial
environments and complies with high EMC requirements. Nevertheless, before installing
your devices you should prepare an EMC plan and identify and take into consideration
possible interference sources.
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.
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
SIWAREX WP251
Manual, 12/2015, A5E37203357A
● 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.
25
Mounting
5.2.3
Coupling mechanisms
5.2.4
Five basic rules for securing EMC
Rule 1: Large area grounding contact
Rule 2: Proper cable routing
Rule 3: Fixing the cable shielding
5.2 EMC-compliant installation
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
Observe these five basic rules to secure EMC.
● When installing the devices, make sure that the surfaces of inactive metal parts are
properly bonded to chassis ground (see following sections).
● Bond all inactive metal parts to chassis ground, ensuring large area and low-impedance
contact (large cross-sections).
● When using screw connections on varnished or anodized metal parts, support contact
with special contact washers or remove the protective insulating finish on the points of
contact.
● Wherever possible, avoid the use of aluminum parts for ground bonding. Aluminum
oxidizes very easily and is therefore less suitable for ground bonding.
● Provide a central connection between chassis ground and the ground/protective
conductor system.
● Organize your wiring system into cable groups (high-voltage/power
supply/signal/measurement/data cables).
● Always route high-voltage and data cables in separate ducts or in separate bundles.
● Install the measurement cables as close as possible to grounded surfaces (e.g.
supporting beans, metal rails, steel cabinet walls).
● Ensure proper fixation of the cable shielding.
● Always use shielded data cables. Always connect both ends of the data cable shielding to
ground on a large area.
● Keep unshielded cable ends as short as possible.
● Always use metal/metalized connector housings only for shielded data cables.
SIWAREX WP251
26 Manual, 12/2015, A5E37203357A
Mounting
Rule 4: Special EMC measures
Rule 5: Homogeneous reference potential
5.3
Mounting on the SIMATIC S7-1200
5.3 Mounting on the SIMATIC S7-1200
● All inductors that are to be controlled should be connected with suppressors.
● For cabinet or enclosure lighting in the immediate range of your controller, use
incandescent lamps or interference suppressed fluorescent lamps.
● Create a homogeneous reference potential and ground all electrical equipment.
● Use sufficiently dimensioned equipotential bonding conductors if potential differences
exist or are expected between your system components. Equipotential bonding is
absolutely mandatory for applications in hazardous areas.
The electronic weighing system described here is a SIMATIC S7-1200 module and can be
directly connected to the automation system's bus system. The 70 mm wide module has very
low installation and cabling requirements.
The module is fitted on a mounting rail, and the bus connection made using the slide switch.
The load cells, power supply and serial interfaces are connected via the screw-type
connectors.
Use of the WP251 in the SIMATIC TIA Portal is described in detail in section 11 of this
manual: → Integration in SIMATIC S7-1200 (Page 185)
SIWAREX WP251
Manual, 12/2015, A5E37203357A
27
Mounting
5.3 Mounting on the SIMATIC S7-1200
SIWAREX WP251
28 Manual, 12/2015, A5E37203357A
6
6.1
Overview
①
24 V connection
⑥
Digital input connection
②
Analog output connection
⑦
Ethernet interface connection
③
Load cell connection
⑧
Calibration bridge connection
④
RS485 interface connection
⑨
Mounting terminals for the calibration protection plate
⑤
Digital output connection
All external connections (with the exception of the Ethernet interface) are made by means of
the screw connectors (terminal block 1 to 4).
Image 6-1 SIWAREX WP251 connection areas
SIWAREX WP251
Manual, 12/2015, A5E37203357A
29
Connection
6.2
24 V connection
Labeling
Function
L +
+24 V voltage supply
6.3
Connecting the load cells
Overview
Rules
Observe the following rules when connecting analog (strain gauge) load cells:
6.2 24 V connection
The 24 V DC supply voltage is connected to the electronic weighing system via the
corresponding terminals.
Table 6- 1 Connection of the 24 V supply
M Ground voltage supply
Sensors equipped with strain gauges (DMS full bridge) can be connected to the SIWAREX
WP251 electronic weighing system. These sensors meet the following requirements.
● Characteristic value 1.... 4 mV/V
● The power supply for the load cells is 4.85 V.
● To check the maximum possible number of load cells that can be connected to a WP251,
the following condition must be met:
– Scale operation without Ex interface: (input resistance of load cell) / (number of load
cells) > 40 Ohm
– Scale operation without Ex interface: (input resistance of load cell) / (number of load
cells) > 50 Ohm
1. The use of a junction box (SIWAREX JB junction box) is required when more than one
load cell is connected (the load cells must be connected in parallel). If the distance of a
load cell to the SIWAREX WP251 or the junction box is greater than the available length
of the load cell connection cable, use the SIWAREX EB extension box.
2. The cable shield is always applied at the cable gland of the junction box (SIWAREX JB)
or the extension box. If there is a risk of equipotential bonding through the cable shield,
connect a equipotential equalization conductor parallel to the load cell cable.
SIWAREX WP251
30 Manual, 12/2015, A5E37203357A
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