ESD CompactPCI CPCI-CAN/200 User manual

CPCI-CAN/200
Hardware Manual Doc.-Nr.: C.2035.21 / Rev 2.2
Page 1 of 31
CPCI-CAN/200
CompactPCI® CAN Interface
Hardware Manual
to Product C.2035.02,
C.2035.04,
C.2035.07

Page 2 of 31
Hardware Manual Doc.-Nr.: C.2035.21 / Rev. 2.2
CPCI-CAN/200
This manual contains important information and instructions on safe and efficient
handling of the CPCI-CAN/200. Carefully read this manual before commencing any
work and follow the instructions.
The manual is a product component, please retain it for future use.
Trademark Notices
CANopen® and CiA® are registered community trademarks of CAN in Automation e.V..
CompactPCI® is a registered trademark of the PCI Industrial Computers Manufacturers Group.
Linux® is the registered trademark of Linus Torvalds in the United States and/or other countries.
QNX® is a registered trademark of QNX Software Systems Limited, and a registered trademark and/or used in certain
jurisdictions.
VxWorks® is a registered trademark of Wind River Systems, Inc.
Windows® is a registered trademark of Microsoft Corporation in the United States and other countries.
All other trademarks, product names, company names or company logos used in this manual are reserved by their
respective owners.
Notes
The information in this document has been carefully checked and is believed to be entirely reliable.
esd electronics makes no warranty of any kind with regard to the material in this document and
assumes no responsibility for any errors that may appear in this document. In particular descriptions
and technical data specified in this document may not be constituted to be guaranteed product
features in any legal sense.
esd electronics reserves the right to make changes without notice to this, or any of its products, to
improve reliability, performance or design.
All rights to this documentation are reserved by esd electronics. Distribution to third parties, and
reproduction of this document in any form, whole or in part, are subject to esd electronics' written
approval.
© 2021 esd electronics gmbh, Hannover
esd electronics gmbh
Vahrenwalder Str. 207
30165 Hannover
Germany
Tel.:
[phone]
Fax:
[phone]
E-Mail:
[email protected]
Internet:
www.esd.eu

CPCI-CAN/200
Hardware Manual Doc.-Nr.: C.2035.21/ Rev. 2.2
Page 3 of 31
Document Information
Document file:
I:\Texte\Doku\MANUALS\CPCI\CAN-200\Englisch\CPCI-CAN200_Hardware-Manual_en_22.docx
Date of print:
2021-07-21
Document-type
number:
DOC0800
Hardware version.:
2.0
Document History
The changes in the document listed below affect changes in the hardware as well as changes in the
description of the facts, only.
Rev.
Chapter
Changes versus previous version
Date
2.1
-
Order information revised, wiring hints revised, editorial revision.
2014-09-25
2.2
-
Classification of Warning Messages and Safety Instructions inserted,
Instructions revised
2021-07-21
1.1
Description of CPCI-CAN/200-2-T version inserted
2, 3.1
Note on availability of CAN 1 inserted
4.
Safety information revised
5.1
Description of Connectors and temperature range revised
5.4
Chapter revised, Description of CAN tools added
9
Declaration of Conformity new
10.1
Description of properties modified, CPCI-CAN/200-2-T version inserted
Technical details are subject to change without further notice.

Page 4 of 31
Hardware Manual Doc.-Nr.: C.2035.21 / Rev. 2.2
CPCI-CAN/200
Classification of Warning Messages and Safety Instructions
This manual contains noticeable descriptions, warning messages and safety instructions, which you
must follow to avoid personal injuries or death and property damage.
This is the safety alert symbol.
It is used to alert you to potential personal injury hazards. Obey all safety messages
and instructions that follow this symbol to avoid possible injury or death.
DANGER, WARNING, CAUTION
Depending on the hazard level the signal words DANGER, WARNING or CAUTION are used to
highlight safety instructions and warning messages. These messages may also include a warning
relating to property damage.
DANGER
Danger statements indicate a hazardous situation which, if not avoided, will result in
death or serious injury.
WARNING.
Warning statements indicate a hazardous situation that, if not avoided, could result in
death or serious injury.
CAUTION
Caution statements indicate a hazardous situation that, if not avoided, could result in
minor or moderate injury.
NOTICE
Notice statements are used to notify people on hazards that could result in things other than personal
injury, like property damage.
NOTICE
This NOTICE statement indicates that the device contains components sensitive to
electrostatic discharge.
NOTICE
This NOTICE statement contains the general mandatory sign and gives information that
must be heeded and complied with for a safe use.
INFORMATION
INFORMATION
Notes to point out something important or useful.

CPCI-CAN/200
Hardware Manual Doc.-Nr.: C.2035.21/ Rev. 2.2
Page 5 of 31
Safety Instructions
●
When working with the CPCI-CAN/200 follow the instructions below and read the manual
carefully to protect yourself from injury and the CPCI-CAN/200 from damage.
●
The device is a built-in component. It is essential to ensure that the device is mounted in a way
that cannot lead to endangering or injury of persons or damage to objects.
●
Do not use damaged or defective cables to connect the CPCI-CAN/200 and follow the CAN
wiring hints in chapter: "Correct Wiring of Electrically Isolated CAN Networks".
●
In case of damages to the device, which might affect safety, appropriate and immediate
measures must be taken, that exclude an endangerment of persons and domestic animals and
property.
●
Current circuits which are connected to the device have to be sufficiently protected against
hazardous voltage (SELV according to EN 60950-1).
●
The CPCI-CAN/200 may only be driven by power supply current circuits, that are contact
protected. A power supply, that provides a safety extra-low voltage (SELV) according to EN
60950-1, complies with these conditions.
●
The device has to be securely installed in the control cabinet before commissioning.
●
Protect the CPCI-CAN/200 from dust, moisture and steam.
●
Protect the CPCI-CAN/200 from shocks and vibrations.
●
The CPCI-CAN/200 may become warm during normal use. Always allow adequate ventilation
around the CPCI-CAN/200 and use care when handling.
●
Do not operate the CPCI-CAN/200 adjacent to heat sources and do not expose it to
unnecessary thermal radiation. Ensure an ambient temperature as specified in the technical
data.
DANGER
Hazardous Voltage - Risk of electric shock due to unintentional contact with
uninsulated live parts with high voltages inside of the system into which the CPCI-
CAN/200 is to be integrated.
→ Disconnect all hazardous voltages (mains voltage) before opening the system.
→ Ensure the absence of voltage before starting any electrical work.
NOTICE
Electrostatic discharges may cause damage to electronic components.
To avoid this, perform the steps described on page 13 before you touch the CPCI-
CAN/200, in order to discharge the static electricity from your body
Qualified Personnel
This documentation is directed exclusively towards personnel qualified in control and automation
engineering. The installation and commissioning of the product may only be carried out by qualified
personnel, which is authorized to put devices, systems, and electric circuits into operation according
to the applicable national standards of safety engineering.
Conformity
The CPCI-CAN/200 is an industrial product and meets the demands of the EU regulations and EMC
standards printed in the conformity declaration at the end of this manual.
Warning:
In a residential, commercial, or light industrial environment the CPCI-CAN/200 may
cause radio interferences in which case the user may be required to take adequate
measures.

Page 6 of 31
Hardware Manual Doc.-Nr.: C.2035.21 / Rev. 2.2
CPCI-CAN/200
The CPCI-CAN/200 is a sub-assembly intended for incorporation into an apparatus by a
manufacturer and NOT by the end user. The manufacturer of the final system must decide whether
additional EMC or EMI protection requirements are necessary.
Intended Use
The intended use of the CPCI-CAN/200 is the operation CompactPCI module in a CompactPCI system.
The guarantee given by esd does not cover damages which result from improper use, usage not in
accordance with regulations or disregard of safety instructions and warnings.
●
The CPCI-CAN/200 is intended for installation in a CompactPCI system.
●
The operation of the CPCI-CAN/200 in hazardous areas, or areas exposed to potentially explosive
materials is not permitted.
●
The operation of the CPCI-CAN/200 for medical purposes is prohibited.
Service Note
The CPCI-CAN/200 does not contain any parts that require maintenance by the user. The CPCI-CAN/200
does not require any manual configuration of the hardware. Unauthorized intervention in the device voids
warranty claims
Disposal
Devices which have become defective in the long run have to be disposed in an appropriate way or have
to be returned to the manufacturer for proper disposal. Please, make a contribution to environmental
protection.

CPCI-CAN/200
Hardware Manual Doc.-Nr.: C.2035.21/ Rev. 2.2
Page 7 of 31
Table of Contents
Safety Instructions ..........................................................................................................................5
1Overview..................................................................................................................................9
1.1 Description of CPCI-CAN/200...........................................................................................9
1.2 Glossary .........................................................................................................................10
2PCB View with Connectors....................................................................................................11
3LEDs......................................................................................................................................12
3.1 Position of the LEDs .......................................................................................................12
3.2 LED Indication ................................................................................................................ 12
4Hardware Installation.............................................................................................................13
5Technical Data.......................................................................................................................15
5.1 General Technical Data ..................................................................................................15
5.2 CAN Interfaces ............................................................................................................... 15
5.3 CompactPCI Bus............................................................................................................16
5.4 Software Support............................................................................................................ 17
6Connector Assignments.........................................................................................................18
6.1 CAN (X301, X311)..........................................................................................................18
7Correct Wiring of Electrically Isolated CAN Networks.............................................................19
7.1Standards concerning CAN Wiring..................................................................................19
7.2 Heavy Industrial Environment (Double Twisted Pair Cable)............................................ 20
7.2.1 General Rules..........................................................................................................20
7.2.2 Device Cabling ........................................................................................................21
7.2.3 Branching ................................................................................................................21
7.2.4 Termination..............................................................................................................21
7.3 Light Industrial Environment (Single Twisted Pair Cable)................................................22
7.3.1 General Rules..........................................................................................................22
7.3.2 Cabling ....................................................................................................................23
7.3.3 Branching ................................................................................................................23
7.3.4 Termination..............................................................................................................23
7.4 Electrical Grounding........................................................................................................ 24
7.5 Bus Length .....................................................................................................................24
7.6 Examples for CAN Cables ..............................................................................................25
7.6.1 Cable for Light Industrial Environment Applications (Two-Wire)............................... 25
7.6.2 Cable for Heavy Industrial Environment Applications (Four-Wire)............................25
8CAN Troubleshooting Guide ..................................................................................................26
8.1 Termination..................................................................................................................... 26
8.2 Electrical Grounding........................................................................................................ 27
8.3 Short Circuit in CAN Wiring.............................................................................................27
8.4CAN_H/CAN_L-Voltage..................................................................................................27
8.5 CAN Transceiver Resistance Test.................................................................................. 28
8.6 Support by esd................................................................................................................28
9Declaration of Conformity.......................................................................................................29
10 Order Information...................................................................................................................30
10.1 Hardware........................................................................................................................ 30
10.2 Software for CPCI-CAN/200 ...........................................................................................30
10.3 Manuals..........................................................................................................................31

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CPCI-CAN/200
List of Tables
Table 1: Description of LEDs........................................................................................................12
Table 2: General Data of the module............................................................................................15
Table 3: Data of the CAN interface...............................................................................................15
Table 4: Data of the CompactPCI interface ..................................................................................16
Table 5: Recommended cable lengths at typical bit rates (with esd-CAN interfaces) ....................24
Table 6: Order information hardware............................................................................................30
Table 7: Order information software for CPCI-CAN/200 ...............................................................30
Table 8: Available Manuals ..........................................................................................................31
List of Figures
Figure 1: Block circuit diagram........................................................................................................9
Figure 2: PCB top view of CPCI-CAN/200-2 .................................................................................11
Figure 3: Connectors and LEDs....................................................................................................12
Figure 4: CAN wiring for heavy industrial environment.................................................................20
Figure 5: Example of proper wiring with single shielded double twisted pair cables .....................21
Figure 6: CAN wiring for light industrial environment....................................................................22
Figure 7: Example for proper wiring with single shielded single twisted pair wires........................23
Figure 8: Simplified diagram of a CAN network............................................................................26
Figure 9: Simplified schematic diagram of ground test measurement...........................................27
Figure 10: Measuring the internal resistance of CAN transceivers...............................................28

Overview
CPCI-CAN/200
Hardware Manual Doc.-Nr.: C.2035.21/ Rev. 2.2
Page 9 of 31
1 Overview
Figure 1: Block circuit diagram
The CPCI-CAN/200 is a passive CompactPCI board with one CAN interface (CPCI-CAN/200-1), or
optional two CAN interfaces (CPCI-CAN/200-2, CPCI-CAN/200-2-T).
Data security and consistency are guaranteed up to 1 Mbit/s.
The ISO 11898-compliant CAN interface allows a maximum data-transfer rate of 1 Mbit/s. Among
many other features of CAN interfaces, the bit rate can be set by software.
The CAN interface is electrically isolated from the other potentials by means of optocouplers and
DC/DC-converters.
The CPCI-CAN/200-2-T version is designed for the extended temperature range (-40°C … +85°C).
1.1 Description of CPCI-CAN/200

Overview
Page 10 of 31
Hardware Manual Doc.-Nr.: C.2035.21 / Rev. 2.2
CPCI-CAN/200
Abbreviations
Abbreviation
Term
API
Application Programming Interface
CAN
Controller Area Network
CPU
Central Processing Unit
CiA
CAN in Automation
HW
Hardware
I/O
Input/Output
LSB
Least Significant Bit
MSB
Most Significant Bit
n.a.
not applicable
OS
Operating System
SDK
Software Development Kit
1.2 Glossary

PCB View with Connectors
CPCI-CAN/200
Hardware Manual Doc.-Nr.: C.2035.21/ Rev. 2.2
Page 11 of 31
2 PCB View with Connectors
Figure 2: PCB top view of CPCI-CAN/200-2
INFORMATION
The interface CAN1 is not equipped on CPCI-CAN/200-1.
NOTICE
Read chapter “Hardware Installation” on page 13, before you start with the installation of
the hardware!
See also page 18 for signal assignment of the CAN connectors.

LEDs
Page 12 of 31
Hardware Manual Doc.-Nr.: C.2035.21 / Rev. 2.2
CPCI-CAN/200
3 LEDs
Figure 3: Connectors and LEDs
INFORMATION
The interface CAN1 is not equipped on CPCI-CAN/200-1.
LED
Colour
Function
Indicator
State
Description
1A
green
not implemented
n.a.
not implemented
1B
green
IRQ CAN 1
off
Interrupt of CAN controller of CAN1 inactive
on
Interrupt of CAN controller of CAN1 active
1C
green
IRQ CAN 0
off
Interrupt of CAN controller of CAN0 inactive
on
Interrupt of CAN controller of CAN0 active
PWR
green
Power
off
Power supply off
on
Power supply on
Table 1: Description of LEDs
3.1 Position of the LEDs
3.2 LED Indication

Hardware Installation
CPCI-CAN/200
Hardware Manual Doc.-Nr.: C.2035.21/ Rev. 2.2
Page 13 of 31
4 Hardware Installation
NOTICE
Read the safety instructions at the beginning of this document carefully before you
start with the hardware installation!
DANGER
Hazardous Voltage - Risk of electric shock due to unintentional contact with uninsulated
live parts with high voltages inside of the system into which the CPCI-CAN/200 is to be
integrated.
→
→
→
Disconnect all hazardous voltages (mains voltage) before opening the system.
Never carry out work while power supply voltage is switched on!
Ensure the absence of voltage before starting any electrical work.
NOTICE
Electrostatic discharges may cause damage to electronic components.
→
→
To avoid this, please discharge the static electricity from your body by touching the
metal case of the CompactPCI system before you touch the CPCI-CAN/200.
Furthermore, you should prevent your clothes from touching the CPCI-CAN/200,
because your clothes might be electrostatically charged as well.
Procedure:
1.
Switch off your CompactPCI system and all connected peripheral devices (monitor, printer,
etc.).
2.
Discharge your body as described above.
3.
Disconnect the system from the mains.
Make sure that no risk arises from the system into which the CPCI-CAN/200 shall be
inserted.
DANGER
Hazardous Voltage
Risk of electric shock due to unintentional contact with uninsulated live parts with high
voltages.
→
→
→
→
Disconnect all hazardous voltages (mains voltage) before opening the system.
If the system does not have a flexible mains cable, but is directly connected to
mains, disconnect the power supply via the safety fuse and make sure that the fuse
cannot switch on again unintentionally (e. g. with caution label).
Ensure the absence of voltage before starting any electrical work.
Cover or block off adjacent live parts.
4.
Open the case if necessary.
5.
Insert the CPCI-CAN/200 board into the selected CompactPCI slot. The CAN module can be
inserted into any 3U-slot.
- Carefully push the board back until it snaps into place.
- Attach the module by means of the front panel screws.
6.
Close the system's case again.
7.
Fix the module.

Hardware Installation
Page 14 of 31
Hardware Manual Doc.-Nr.: C.2035.21 / Rev. 2.2
CPCI-CAN/200
8.
Connect the CAN interfaces via the connectors in the front panel of the CPCI-CAN/200:
Please note that the CAN bus must be terminated at both ends! esd offers special T-connectors
and termination connectors for external termination. Additionally, the CAN_GND signal must
be connected to earth at exactly one point in the CAN network.
For details, please read chapter “Correct Wiring Electrically Isolated CAN Networks” from
page 19.
The first CAN interface (CAN network 0) is connected via the DSUB-connector (X301) and the
second CAN interface (CAN network 1) is connected via the DSUB-connector (X311).
9.
Connect the system to mains again (mains connector or safety fuse).
10.
Switch on the system and the peripheral devices.
11.
End of hardware installation.
12.
Continue with the software installation as described in the manual
“NTCAN-API: Driver Installation Guide”.

Technical Data
CPCI-CAN/200
Hardware Manual Doc.-Nr.: C.2035.21/ Rev. 2.2
Page 15 of 31
5 Technical Data
Power supply voltage
nominal voltage: 5 V ±5%
3.3 V ±5%
current (max.): for 3.3 V I3.3VMAX = 210 mA
for 5 V (1x CAN): I5VMAX = 300 mA
for 5 V (2x CAN): I5VMAX = 400 mA
Connectors
X100 (132-pin post connector)
X301 (DSUB9/plug)
- CompactPCI board connector
- CAN net 0
Connectors only equipped in the 2x CAN versions
CPCI-CAN/200-2 and CPCI-CAN/200-2-T:
X311 (DSUB9/plug)
X300 (8-pole pin strip)
X310 (8-pole pin strip)
- CAN net 1
- optional interface adapter net 0
- optional interface adapter net 1
Only for test- and programming purposes:
X210 (7-pole pin strip)
- ISP-programming
Temperature range
CPCI-CAN/200-1,
CPCI-CAN/200-2: 0....50 °C
CPCI-CAN/200-2-T: -40....85 °C
Humidity
max. 90%, non-condensing
Dimensions
3U, 4HP CompactPCI board
100 mm x 160 mm (without connectors)
Weight
170 g
Table 2: General Data of the module
Number of CAN interfaces
CPCI-CAN/200-1: 1x CAN,
CPCI-CAN/200-2: 2x CAN
CAN controller
SJA1000
CAN protocol
according to ISO 11898-1
Physical CAN Layer
High-speed CAN interface according to ISO 11898-2,
bit rate up to 1 Mbit/s
Electrical isolation
the CAN interfaces are electrically isolated from each other and
from the CompactPCI bus potentials via optocouplers and
DC/DC-converters
Bus termination
terminating resistor must be set externally, if required
Connector
DSUB9, male contacts
Table 3: Data of the CAN interface
5.1 General Technical Data
5.2 CAN Interfaces

Technical Data
Page 16 of 31
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CPCI-CAN/200
Host bus
PCI-bus according to PCI-Local Bus Specification 2.1
PCI-data/address bus
32-bit
Controller
PLX 9030
Interrupt
interrupt signal A
Board dimension
according to CompactPCI Specification, Rev. 1.0
Connectors
Connector coding
Universal Board, not keyed (3.3 V or 5 V signalling voltage)
Table 4: Data of the CompactPCI interface
5.3 CompactPCI Bus

Technical Data
CPCI-CAN/200
Hardware Manual Doc.-Nr.: C.2035.21/ Rev. 2.2
Page 17 of 31
CAN layer 2 drivers for Windows®and Linux®are included in delivery. CAN layer 2 drivers e. g. for
QNX®, RTX® and RTX64® can be ordered separately.
Libraries for the higher layer protocols CANopen and J1939 are available.
For detailed information about the driver availability for your operating system, please contact our
sales team: ([e-mail])
The CAN layer 2 (CAN-API) software installation and the software drivers are described in the
manual:
“NTCAN-API Part 1: Structure, Function and C/C++ API” Application Developers Manual and
“NTCAN-API Part 2: Installation, Configuration and Firmware Update” Installation Guide
(esd-order No.: C.2001.21)
CAN Tools
esd offers additional free-of-charge tools which support efficient setup and analysis of CAN
applications and networks.
The CAN Tools are operational with all esd PC-CAN interfaces (e. g. PCIe, USB, EtherCAN/2 ...)
The following CAN Tools are available:
CANreal
Display and record of CAN
message frames
CANplot
Graphical display of CAN data
CANrepro
Replay of pre-recorded CAN
messages
CANscript
Python-based scripting tool
COBview
Analysis and diagnostics of
CANopen®nodes
System Requirements:
-Windows 32-bit or 64-bit system
-30 MB free HD drive space
-esd CAN driver installed
As part of the esd software development kit (CAN SDK) of the NTCAN-API the CAN Tools are
included in delivery of the CAN-CD.
The CAN SDK can also be downloaded free-of-charge from the esd website.
5.4 Software Support

Connector Assignments
Page 18 of 31
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CPCI-CAN/200
6 Connector Assignments
The signals are identically assigned to the connector of interface CAN0 (X301) and to the optional
interface CAN1 (X311).
Device connector: 9-pin DSUB connector, pin contacts
Pin Position:
Pin Assignment:
Signal
Pin
Signal
1
Reserved
CAN_GND
6
2
CAN_L
CAN_H
7
3
CAN_GND
Reserved
8
4
Reserved
Reserved
9
5
Shield
Signal Description:
CAN_L, CAN_H
CAN signal lines
CAN_GND
reference potential of the local CAN physical layer
Shield
shielding (connected with the case of the 9-pin DSUB connector)
Reserved
reserved for future applications, do not connect!
1 2 3 4 5
6789
6.1 CAN (X301, X311)

Correct Wiring of Electrically Isolated CAN Networks
CPCI-CAN/200
Hardware Manual Doc.-Nr.: C.2035.21/ Rev. 2.2
Page 19 of 31
7 Correct Wiring of Electrically Isolated
CAN Networks
NOTICE
This chapter applies to CAN networks with bit rates up to 1 Mbit/s.
If you work with higher bit rates, as for example used for CAN FD, the information given in
this chapter must be examined for applicability in each individual case.
For further information refer to the CiA® CAN FD guidelines and recommendations
(https://www.can-cia.org/).
For the CAN wiring all applicable rules and regulations (EU, DIN), e.g. regarding electromagnetic
compatibility, security distances, cable cross-section or material, have to be observed.
The flexibility in CAN network design is one of the key strengths of the various extensions and
additional standards like e.g. CANopen, ARINC825, DeviceNet and NMEA2000 that have been built
on the original ISO 11898-2 CAN standard. In using this flexibility comes the responsibility of good
network design and balancing these tradeoffs.
Many CAN organizations and standards have scaled the use of CAN for applications outside the
original ISO 11898. They have made system level tradeoffs for data rate, cable length, and parasitic
loading of the bus.
However, for CAN network design margin must be given for signal loss across the complete system
and cabling, parasitic loadings, network imbalances,ground offsets against earth potential and signal
integrity. Therefore, the practical maximum number of nodes, bus length and stub length are
typically much lower.
esd has concentrated her recommendations concerning CAN wiring on the specifications of the
ISO 11898-2. Thus, this wiring hints forgoes to describe the special features of the derived standards
CANopen, ARINC825, DeviceNet and NMEA2000.
The consistent compliance to ISO 11898-2 offers significant advantages:
●Durable operation due to well proven design specifications
●Minimizing potential failures due to sufficient margin to physical limits
●Trouble-free maintenance during future network modifications or during fault diagnostics
due to lack of exceptions
Of course, reliable networks can be designed according the specifications of CANopen, ARINC825,
DeviceNet and NMEA2000, however it must be observed that it is strictly not recommended to
mix the wiring guidelines of the various specifications!
7.1 Standards concerning CAN Wiring

Correct Wiring of Electrically Isolated CAN Networks
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CPCI-CAN/200
7.2.1General Rules
NOTICE
esd only grants the compliance with directive 2014/30/EU, if the CAN wiring is carried out
with single shielded double twisted pair cables that match the requirements of
ISO 11898-2.
The following general rules for the CAN wiring with single shielded double twisted pair cable should
be followed:
1
A cable type with a wave impedance of about 120 Ω±10% with an adequate conductor cross-section
(≥ 0.22 mm²) has to be used. The voltage drop over the wire has to be considered.
2
For heavy industrial environment use a four-wire CAN cable.
Connect
•
•
•
two twisted wires to the data signals (CAN_H, CAN_L) and
the other two twisted wires to the reference potential (CAN_GND) and
the cable shield to functional earth (FE) at least at one point.
3
The reference potential CAN_GND has to be connected to the functional earth (FE) at exactly one point.
4
A CAN bus line must not branch (exception: short cable stubs) and has to be terminated with the
characteristic impedance of the line (generally 120 Ω±10%) at both ends (between the signals CAN_L
and CAN_H and not to CAN_GND).
5
Keep cable stubs as short as possible (l < 0.3 m).
6
Select a working combination of bit rate and cable length.
7
Keep away CAN cables from disturbing sources. If this can not be avoided, double shielded cables are
recommended.
Figure 4: CAN wiring for heavy industrial environment
7.2 Heavy Industrial Environment (Double Twisted Pair
Cable)