turck BL20 User manual

BL20 –
GATEWAY
FOR
Modbus RTU
Sense it! Connect it! Bus it! Solve it!

All brand and product names are trademarks or registered trade marks of the owner
concerned.
Edition 05/2013
© Hans Turck GmbH, Muelheim an der Ruhr
All rights reserved, including those of the translation.
No part of this manual may be reproduced in any form (printed, photocopy, microfilm or any
other process) or processed, duplicated or distributed by means of electronic systems
without written permission of Hans Turck GmbH & Co. KG, Muelheim an der Ruhr.
Subject to alterations without notice

D301295 0513 - BL20 - Modbus RTU i
Table of Contents
1Aboutthismanual
1.1 Documentation concept .................................................................................................................................1-2
1.2 Description of symbols used ..........................................................................................................................1-3
1.3 General ............................................................................................................................................................1-4
1.3.1 Prescribed use .........................................................................................................................................................................................1-4
1.3.2 Notes concerning planning/ installation of this product ........................................................................................................1-4
2 BL20-philosophy
2.1 The basic concept ............................................................................................................................................2-2
2.1.1 Flexibility ...................................................................................................................................................................................................2-2
2.1.2 Compactness ...........................................................................................................................................................................................2-2
2.1.3 Easy to handle .........................................................................................................................................................................................2-2
2.2 BL20 components ............................................................................................................................................2-3
2.2.1 Gateways ...................................................................................................................................................................................................2-3
2.2.2 Power distribution modules...............................................................................................................................................................2-4
2.2.3 Electronics modules (standard product line)...............................................................................................................................2-5
2.2.4 ECO electronics modules.....................................................................................................................................................................2-6
2.2.5 Base modules...........................................................................................................................................................................................2-7
2.2.6 End plate....................................................................................................................................................................................................2-8
2.2.7 End bracket...............................................................................................................................................................................................2-8
2.2.8 Jumpers......................................................................................................................................................................................................2-9
2.2.9 Shield connection gateway ............................................................................................................................................................. 2-10
3 Technical features
3.1 Introduction .....................................................................................................................................................3-2
3.2 Function ...........................................................................................................................................................3-3
3.3 Technical data..................................................................................................................................................3-4
3.3.1 Block diagram ..........................................................................................................................................................................................3-5
3.3.2 General technical data of a station .................................................................................................................................................3-5
3.3.3 Technical data for the push-in tension clamp terminals ........................................................................................................3-8
3.4 Connection options at the gateway...............................................................................................................3-9
3.4.1 Power supply ...........................................................................................................................................................................................3-9
3.4.2 Fieldbus connection........................................................................................................................................................................... 3-10
3.4.3 Service interface connection (mini USB female connector) ................................................................................................ 3-11
3.5 Configuration of the field bus parameters................................................................................................. 3-12
3.5.1 Standard mode (configuration via DIP-switches).................................................................................................................... 3-12
3.6 Synchronization of the station configuration............................................................................................ 3-16
3.6.1 DIP-switch CFG..................................................................................................................................................................................... 3-16
3.6.2 Extended mode (I/O-ASSISTANT 3 (FDT/DTM)......................................................................................................................... 3-17
3.7 Status indicators/diagnostic messages gateway....................................................................................... 3-18
3.7.1 Diagnosis via LEDs .............................................................................................................................................................................. 3-18

D301295 0513 - BL20 - Modbus RTUii
4 Implementation of Modbus TCP
4.1 Common Modbus description ....................................................................................................................... 4-2
4.1.1 Protocol description ............................................................................................................................................................................. 4-3
4.1.2 Data model............................................................................................................................................................................................... 4-4
4.2 Implemented Modbus functions ................................................................................................................... 4-6
4.3 Modbus registers ............................................................................................................................................ 4-7
4.4 Structure of the packed in-/ output process data ...................................................................................... 4-12
4.4.1 Packed input process data ...............................................................................................................................................................4-13
4.4.2 Packed output process data ............................................................................................................................................................4-13
4.5 Data width of the I/O-modules in the modbus-register area ....................................................................4-14
4.6 Register 0×100C: "Gateway status"............................................................................................................. 4-16
4.7 Register 0×113C und 0×113D: "Restore Modbus-Connection-Parameters" ........................................... 4-16
4.8 Register 0×113E und 0×113F: "Save Modbus-Connection-Parameters" ................................................. 4-17
4.9 The Service-Object........................................................................................................................................ 4-17
4.10 Bit areas: mapping of input-discrete- and coil-areas................................................................................. 4-20
4.11 Error behavior of outputs (watchdog) ........................................................................................................ 4-20
4.12 Parameters of the modules. ......................................................................................................................... 4-21
4.12.1 Digital input modules ........................................................................................................................................................................4-21
4.12.2 Analog input modules .......................................................................................................................................................................4-22
4.12.3 Analog output modules ....................................................................................................................................................................4-30
4.12.4 Technology modules..........................................................................................................................................................................4-35
4.13 Diagnostic messages of the modules.......................................................................................................... 4-45
4.13.1 Power distribution modules ............................................................................................................................................................4-45
4.13.2 Digital input modules ........................................................................................................................................................................4-46
4.13.3 Analog input modules .......................................................................................................................................................................4-46
4.13.4 Digital output modules .....................................................................................................................................................................4-49
4.13.5 Analog output modules ....................................................................................................................................................................4-51
4.13.6 Technology modules..........................................................................................................................................................................4-52
5 Application example: Modbus
5.1 Used hard-/ software ...................................................................................................................................... 5-2
5.1.1 Hardware .................................................................................................................................................................................................. 5-2
5.1.2 Software .................................................................................................................................................................................................... 5-2
5.2 Configuring the hardware.............................................................................................................................. 5-3
5.2.1 Connection of the BL20-gateway in the example ..................................................................................................................... 5-4
5.3 Operation with CoDeSys ................................................................................................................................ 5-5
5.3.1 Predefined feature sets........................................................................................................................................................................ 5-5
5.3.2 Creating a new project ........................................................................................................................................................................ 5-6
5.3.3 Defining the communication settings ........................................................................................................................................... 5-8
5.3.4 Adding the Modbus COM port ......................................................................................................................................................5-10
5.3.5 Adding the serial Modbus master .................................................................................................................................................5-12
5.3.6 Adding a Modbus-slave.....................................................................................................................................................................5-13
5.3.7 Programming (example program) ................................................................................................................................................5-16

D301295 0513 - BL20 - Modbus RTU iii
5.3.8 CoDeSys: Global variables................................................................................................................................................................ 5-17
5.3.9 Modbus channels ................................................................................................................................................................................ 5-18
5.3.10 Building, login and start.................................................................................................................................................................... 5-30
5.3.11 Reading out the process data......................................................................................................................................................... 5-31
5.3.12 Diagnosis evaluation.......................................................................................................................................................................... 5-32
6 Guidelines for station planning
6.1 Module arrangement ......................................................................................................................................6-2
6.1.1 Random module arrangement..........................................................................................................................................................6-2
6.1.2 Complete planning................................................................................................................................................................................6-3
6.1.3 Maximum system extension ..............................................................................................................................................................6-3
6.2 Power supply ...................................................................................................................................................6-6
6.2.1 Power supply to the gateway ............................................................................................................................................................6-6
6.2.2 Module bus refreshing .........................................................................................................................................................................6-6
6.2.3 Creating potential groups...................................................................................................................................................................6-6
6.2.4 C-rail (cross connection) ......................................................................................................................................................................6-7
6.2.5 Direct wiring of relay modules ..........................................................................................................................................................6-9
6.3 Protecting the service interface on the gateway ....................................................................................... 6-10
6.4 Plugging and pulling electronics modules................................................................................................. 6-10
6.5 Extending an existing station...................................................................................................................... 6-10
6.6 Firmware download ..................................................................................................................................... 6-11
7 Guidelines for electrical installation
7.1 General notes...................................................................................................................................................7-2
7.1.1 General.......................................................................................................................................................................................................7-2
7.1.2 Cable routing ...........................................................................................................................................................................................7-2
7.1.3 Lightning protection.............................................................................................................................................................................7-3
7.1.4 Transmission media...............................................................................................................................................................................7-3
7.2 Potential relationships....................................................................................................................................7-4
7.2.1 General.......................................................................................................................................................................................................7-4
7.3 Electromagnetic compatibility(EMC ..............................................................................................................7-5
7.3.1 Ensuring electromagnetic compatibility .......................................................................................................................................7-5
7.3.2 Grounding of inactive metal components....................................................................................................................................7-5
7.3.3 PE connection..........................................................................................................................................................................................7-5
7.3.4 Earth-free operation..............................................................................................................................................................................7-5
7.3.5 Mounting rails..........................................................................................................................................................................................7-6
7.4 Shielding of cables ..........................................................................................................................................7-7
7.5 Potential compensation..................................................................................................................................7-8
7.5.1 Switching inductive loads...................................................................................................................................................................7-8
7.5.2 Protection against Electrostatic Discharge (ESD) .......................................................................................................................7-8
8 BL20-Approvals for Zone 2/ Division 2

D301295 0513 - BL20 - Modbus RTUiv
9 Appendix
9.1 Data image of the technology modules........................................................................................................ 9-2
9.1.1 1RS232/ 1RS485-module..................................................................................................................................................................... 9-2
9.1.2 SSI module................................................................................................................................................................................................ 9-6
9.1.3 SWIRE-module ......................................................................................................................................................................................9-13
9.1.4 Encoder/PWM-module: BL20-E-2CNT-2PWM............................................................................................................................9-15
9.1.5 RFID-module: BL20-2RFID-S.............................................................................................................................................................9-15
9.2 Ident codes the BL20-modules.................................................................................................................... 9-16
10 Index

D301295 0513 - BL20 - Modbus RTU 1-1
1 About this manual
1.1 Documentation concept ............................................................................................................................... 2
1.2 Description of symbols used ....................................................................................................................... 3
1.3 General .......................................................................................................................................................... 4
1.3.1 Prescribed use .......................................................................................................................................................................................4
1.3.2 Notes concerning planning/ installation of this product ......................................................................................................4

About this manual
D301295 0513 - BL20 - Modbus RTU1-2
1.1 Documentation concept
This manual contains all information about the Modbus RTU-Gateway of the product line BL20
(BL20-E-GW-RS-MB-ET).
The following chapter contain a short BL20-description, a description of the used field bus system,
exact information about function and structure of the field bus specific BL20-gateway as well as all bus
specific information concerning the connection to automation devices, the maximum system
extension etc.
The bus-independent I/O-modules of the BL20-system as well as all bus independent information as
mounting, labeling etc. are described in a separate manual.
BL20 I/O-modules (TURCK-documentation no.: German D300716; English D300717)
In addition to that, the manual contains a short description of the I/O-ASSISTANT, the project planning
and configuration software tool for TURCK I/O-systems-

D301295 0513 - BL20 - Modbus RTU 1-3
Description of symbols used
1.2 Description of symbols used
Warning
This sign can be found next to all notes that indicate a source of hazards. This can refer to
danger to personnel or damage to the system (hardware and software) and to the facility.
This sign means for the operator: work with extreme caution.
Attention
This sign can be found next to all notes that indicate a potential hazard.
This can refer to possible danger to personnel and damages to the system (hardware and
software) and to the facility.
Note
This sign can be found next to all general notes that supply important information about one
or more operating steps.
These specific notes are intended to make operation easier and avoid unnecessary work due
to incorrect operation.

About this manual
D301295 0513 - BL20 - Modbus RTU1-4
1.3 General
This manual includes all information necessary for the prescribed use of the BL20-E-GW-RS-MB/ET. It
has been specially conceived for personnel with the necessary qualifications.
1.3.1 Prescribed use
Appropriate transport, storage, deployment and mounting as well as careful operating and thorough
maintenance guarantee the trouble-free and safe operation of these devices.
1.3.2 Notes concerning planning/ installation of this product
Attention
Please read this section carefully. Safety aspects cannot be left to chance when dealing with
electrical equipment.
Warning
The devices described in this manual must be used only in applications prescribed in this
manual or in the respective technical descriptions, and only with certified components and
devices from third party manufacturers.
Warning
All respective safety measures and accident protection guidelines must be considered
carefully and without exception.

D301295 0513 - BL20 - Modbus RTU 2-1
2 BL20-philosophy
2.1 The basic concept.......................................................................................................................................... 2
2.1.1 Flexibility .................................................................................................................................................................................................2
2.1.2 Compactness .........................................................................................................................................................................................2
2.1.3 Easy to handle .......................................................................................................................................................................................2
2.2 BL20 components.......................................................................................................................................... 3
2.2.1 Gateways.................................................................................................................................................................................................3
– ECO-gateways ...................................................................................................................................................................................3
– Gateways with integrated power supply ................................................................................................................................4
– Gateways without integrated power supply .........................................................................................................................4
2.2.2 Power distribution modules.............................................................................................................................................................4
2.2.3 Electronics modules (standard product line).............................................................................................................................5
2.2.4 ECO electronics modules...................................................................................................................................................................6
2.2.5 Base modules.........................................................................................................................................................................................7
2.2.6 End plate..................................................................................................................................................................................................8
2.2.7 End bracket.............................................................................................................................................................................................8
2.2.8 Jumpers ...................................................................................................................................................................................................9
2.2.9 Shield connection gateway........................................................................................................................................................... 10

BL20-philosophy
D301295 0513 - BL20 - Modbus RTU2-2
2.1 The basic concept
BL20 is a modular I/O system for use in industrial automation. It connects the sensors and actuators in
the field with the higher-level master.
BL20 offers modules for practically all applications:
Digital input and output modules
Analog input and output modules
Technology modules (counters, RS232 interface...)
A complete BL20 station counts as one station on the bus and therefore occupies one fieldbus address
in any given fieldbus structure.
A BL20 station consists of a gateway, power distribution modules and I/O modules.
The connection to the relevant fieldbus is made via the bus-specific gateway, which is responsible for
the communication between the BL20 station and the other fieldbus stations.
The communication within the BL20 station between the gateway and the individual BL20 modules is
regulated via an internal module bus.
2.1.1 Flexibility
All BL20 stations can be planned to accommodate the exact number of channels to suit your needs,
because the modules are available with different numbers of channels in block and slice design.
A BL20 station can contain modules in any combination, which means it is possible to adapt the system
to practically all applications in automated industry.
2.1.2 Compactness
The slim design of the BL20 modules (standard gateway 50.4 mm / 1.98 inch, ECO gateway 34 mm/ 1.34
inch, standard slice 12.6 mm / 0.49 inch, ECO slice 13 mm / 0.51 inch and block 100.8 mm / 3.97 inch)
and their low overall height favor the installation of this system in confined spaces.
2.1.3 Easy to handle
All BL20 modules of the standard line, with the exception of the gateway, consist of a base module and
an electronics module.
The gateway and the base modules are snapped onto a mounting rail. The electronics modules are
plugged onto the appropriate base modules.
The base modules of the standard line are designed as terminal blocks. The wiring is secured by tension
clamp or screw connection.
The electronics modules can be plugged or pulled when the station is being commissioned or for
maintenance purposes, without having to disconnect the field wiring from the base modules.
The ECO electronics modules combine base module and electronics module in one housing. All BL20-
ECO modules can be used with the standard products with tension clamp connection technology.
Note
The gateway is the only fieldbus-dependent module on a BL20 station. All other BL20
modules are not dependent on the fieldbus used.

D301295 0513 - BL20 - Modbus RTU 2-3
BL20 components
2.2 BL20 components
2.2.1 Gateways
The gateway connects the fieldbus to the I/O modules. It is responsible for handling the entire process
data and generates diagnostic information for the higher-level master and the software tool PACTware
with the respective TURCK-DTMs (I/O-ASSISTANT).
ECO-gateways
The BL20-ECO gateways enlarge the product portfolio of BL20. They offer an excellent cost/
performance ratio.
Further advantages of the gateways in the ECO-housing:
At the moment available for PROFIBUS-DP, DeviceNet, CANopen, Modbus TCP, Modbus RTU/
ASCII, EtherNet/IP, EtherCAT and PROFINET.
Low required space: width 34 mm/ 1.34 inch minimal space requirements
Can be combined with all existing standard modules (with tension clamp connection technology)
and ECO modules
Simple wiring with "Push-in" tension clamp terminals, via DeviceNet-Open Style Connector or via
Ethernet RJ45-connectors
Automatic bit rate detection for PROFIBUS-DP and DeviceNet
Setting of fieldbus address and bus terminating resistor (PROFIBUS-DP, DeviceNet, CANopen,
Modbus RTU/ASCII) via DIP-switches
Service interface for commissioning with I/O-ASSISTANT 3 (FDT/DTM), without PLC.
Figure 2-1:
Gateway
BL20-E-GW-RS-
MB/ET

BL20-philosophy
D301295 0513 - BL20 - Modbus RTU2-4
Gateways with integrated power supply
All actual BL20-gateways provide an integrated power supply unit for supplying the gateway and the
connected modules.
It is not necessary to supply the station using a special supply module with a separate voltage.
Gateways without integrated power supply
2.2.2 Power distribution modules
The power for gateways and I/O modules is conntecte to the power supply modules. therefore, it is not
necessary to supply each individual module with a separate voltage.
Note
The gateways without integrated power supply unit need an additional power supply
module (bus refreshing module) which feeds the gateway an the connected I/O modules.
Figure 2-2:
Power distribu-
tion module

D301295 0513 - BL20 - Modbus RTU 2-5
BL20 components
2.2.3 Electronics modules (standard product line)
The standard electronics modules contain the I/O-functions of the BL20 modules (power distribution
modules, digital and analog input/output modules, and technology modules).
They are plugged onto the base modules and are not directly connected to the wiring
and can be plugged or pulled when the station is being commissioned or for maintenance purposes,
without having to disconnect the field wiring from the base modules.
Figure 2-3:
Electronics
module in slice
design (left) and
in Block design
(right)

BL20-philosophy
D301295 0513 - BL20 - Modbus RTU2-6
2.2.4 ECO electronics modules
New ECONOMY modules with a high signal density and exceptionally low channel price expand the
BL20 I/O bus terminal system.
Depending on type, up to 16 digital inputs and outputs can be connected on only 13 mm. This high
connection density considerably reduces the mounting width required for typical applications.
All advantages at a glance:
Space saving thanks to 16 channels on 13 mm/ 0.51 inch width
Cost saving thanks to electronics with integrated connection level
High signal density
Tool-less connection via "push-in" spring-type terminal technology for simple and fast mounting
Flexibility in combining them with standard I/O-modules in tension clamp technology, the
standard- and the ECO-gateways.
Simple assembly reduces error sources
Figure 2-4:
ECO I/O-module

D301295 0513 - BL20 - Modbus RTU 2-7
BL20 components
2.2.5 Base modules
The field wiring is connected to the base modules. These are constructed as terminals in block and slice
designs and are available in the following variations with either tension clamp or screw connections: 2-
/3-wire (2-channel), 4-wire (2-channel) and 4x2-/3-wire (4-channel).
Figure 2-5:
Base module
with tension
clamp connec-
tion
Figure 2-6:
Base module
with screw
connection
Figure 2-7:
Base module in
block design

BL20-philosophy
D301295 0513 - BL20 - Modbus RTU2-8
2.2.6 End plate
An end plate on the right-hand side physically completes the BL20 station. An end bracket mounted
into the end plate ensures that the BL20 station remains secure on the mounting rail even when
subjected to vibration.
2.2.7 End bracket
A second end bracket to the left of the gateway is necessary, as well as the one mounted into the end
plate to secure the station.
Figure 2-8:
End plate
Figure 2-9:
End bracket
Note
The end plate and two end brackets are delivered with the gateway.

D301295 0513 - BL20 - Modbus RTU 2-9
BL20 components
2.2.8 Jumpers
Jumpers (QVRs) are used to bridge a connection level of a 4-wire base module. They can be used to
connect potentials in relay modules (bridging the relay roots); thus considerably reducing the amount
of wiring.
Labels: for labeling BL20 electronics modules.
Markers: for colored identification of connection levels of BL20 base modules.
Dekafix connector markers: for numbering the mounting slots on BL20 base modules.
Figure 2-10:
Jumpers
Figure 2-11:
Marking mate-
rial

BL20-philosophy
D301295 0513 - BL20 - Modbus RTU2-10
2.2.9 Shield connection gateway
If the gateway is wired directly to the fieldbus, it is possible to shield the connection using a special
gateway-shielding connection attachment (BS3511/KLBUE4-31.5).
Figure 2-12:
Shield connec-
tion (gateway)