ESD CAN-USB/Micro User manual

CAN-USB/Micro
Small CAN USB Interface
in DSUB9 Enclosure
Manual
to Product C.2068.xx
CAN-USB/Micro Manual • Doc. No.: C.2068.21 / ev. 1.2 Page 1 of 23
esd electronic system design gmbh
Vahrenwalder Str. 207 • 30165 Hannover • ermany
http://www.esd.eu
Phone: [phone] • Fax: [phone]

N O T E
The information in this document has been carefully checked and is believed to be entirely reliable.
esd 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 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. Distribution to third parties, and reproduction
of this document in any form, whole or in part, are subject to esd's written approval.
© 2014 esd electronic system design gmbh, Hannover
esd electronic system design gmbh
Vahrenwalder Str. 207
30165 Hannover
Germany
Phone: [phone]
Fax: [phone]
E-Mail: [email protected]
Internet: www.esd.eu
Trademark Notices
CANopen® and CiA® are registered community trademarks of CAN in Automation e.V.
Windows® is a registered trademark of Microsoft Corporation in the United States and other countries.
Linux® is the registered trademark of Linus Torvalds in the United States and/or other countries.
Free TOSTM is a trademark of eal Time Engineers Ltd.
All other trademarks, product names, company names or company logos used in this manual are reserved by their
respective owners.
Page 2 of 23 Manual • Doc. No.: C.2068.21 / ev. 1.2 CAN-USB/Micro

Document file I:\Texte\Doku\MANUALS\CAN\CAN-USB-Micro\CAN-USB-Micro_Manual_en_12.odt
Date of print 2014-01-28
Document type
number DOC0800
Hardware version 1.1
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.
Revision Chapter Changes versus previous version Date
1.2
5.4 Software support per default via NTCAN driver.
2014-01-179. EC declaration of conformity updated.
10. Order information updated.
1.1
5.4, 12. Notes on software driver support inserted.
2011-06-01
7. Documentation corrected: CAN interface is not electrically isolated. Editorial
revision of the chapter.
8. CAN transceiver test revised. Editorial revision of the chapter.
12. Order information moved to chapter 12.
1.0 - First version 2011-01-28
Technical details are subject to change without further notice.
CAN-USB/Micro Manual • Doc. No.: C.2068.21 / ev. 1.2 Page 3 of 23

Safety Instructions
● When working with CAN-USB/Micro follow the instructions below and read the manual carefully to protect yourself from
injury and the CAN-USB/Micro from damage.
● Do not open the housing of the CAN-USB/Micro.
● Never let liquids get inside the CAN-USB/Micro. Otherwise, electric shocks or short circuits may result.
● Protect the CAN-USB/Micro from dust, moisture and steam.
● Protect the CAN-USB/Micro from shocks and vibrations.
● The CAN-USB/Micro may become warm during normal use. Always allow adequate ventilation around the CAN-
USB/Micro and use care when handling.
● Do not operate the CAN-USB/Micro adjacent to heat sources and do not expose it to unnecessary thermal radiation.
Ensure an ambient temperature as specified in the technical data.
● Do not use damaged or defective cables to connect the CAN-USB/Micro and follow the CAN wiring hints in chapter:
"Correctly Wiring 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 objects.
● Current circuits which are connected to the device have to be sufficiently protected against hazardous voltage (SELV
according to EN 60950-1).
● The CAN-USB/Micro may only be driven by power supply current circuits, that are contact protected.
A power supply, that provides a safety extra-low voltage (SELV or PELV) according to EN 60950-1, complies with this
conditions.
Qualified Personal
This documentation is directed exclusively towards qualified personal.
The installation and commissioning of the product may only be carried out by qualified personal, which is
authorized to put devices, systems and electric circuits into operation according to the applicable national
standards of safety engineering.
Conformity
The CAN-USB/Micro is designed for residential, commercial and light industrial environment and meets the
demands of the EU regulations and EMC standards printed in the conformity declaration at the end of this
manual.
Warning In an industrial environment the CAN-USB/Micro may be affected by radio interferences. In this
case the user may be required to take adequate measures.
Intended Use
The intended use of the CAN-USB/Micro is the operation as USB-CAN interface.
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 operation of the CAN-USB/Micro in hazardous areas, or areas exposed to potentially explosive
materials is not permitted.
● The operation of the CAN-USB/Micro for medical purposes is prohibited.
Service Note
The CAN-USB/Micro does not contain any parts that require maintenance by the user. The CAN-USB/Micro
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.
Page 4 of 23 Manual • Doc. No.: C.2068.21 / ev. 1.2 CAN-USB/Micro

Table of contents
1. Overview......................................................................................................................................7
2. View of the Connectors................................................................................................................8
3. Hardware Installation....................................................................................................................9
4. LED Description.........................................................................................................................10
5. Summary of Technical Data.......................................................................................................11
5.1 General Technical Data.......................................................................................................11
5.2 USB Interface .....................................................................................................................11
5.3 CAN Interface......................................................................................................................11
5.4 Software Support.................................................................................................................12
5.5 Firmware License.................................................................................................................12
6. Connector Assignment...............................................................................................................13
6.1 USB.....................................................................................................................................13
6.2 CAN ....................................................................................................................................14
7. Correctly Wiring of CAN Networks..............................................................................................15
7.1 General ules......................................................................................................................15
7.2 Cabling................................................................................................................................16
7.3 Termination..........................................................................................................................16
7.4 Earthing...............................................................................................................................17
7.5 Bus Length...........................................................................................................................17
7.6 Examples for CAN Cables...................................................................................................18
8. CAN-Bus Troubleshooting Guide...............................................................................................19
8.1 Termination..........................................................................................................................19
8.2 Electrical Grounding.............................................................................................................20
8.3 Short Circuit in CAN Wiring..................................................................................................20
8.4 CAN_H/CAN_L-Voltage ......................................................................................................20
8.5 CAN Transceiver esistance Test ......................................................................................21
9. Declaration of Conformity...........................................................................................................22
10. Order Information.....................................................................................................................23
CAN-USB/Micro Manual • Doc. No.: C.2068.21 / ev. 1.2 Page 5 of 23

Overview
1. Overview
Figure 1 Block-circuit diagram of the CAN-USB/Micro
The CAN-USB/Micro is a very small, low cost CAN-USB interface for PCs, that fits into a DSUB9
enclosure. The A M Cortex-M3 micro controller controls the CAN data. The non isolated CAN
interface is powered by USB.
The CAN-USB/Micro supports the USB 2.0 full-speed interface with data rates up to 12 MBit/s.
Software drivers for Windows® are included in delivery. Linux® is supported via Linux CAN
(SocketCAN) and NTCAN wrapper library. Drivers for other operating systems are available on
request.
Libraries for the higher layer protocols CANopen and J1939 are available. Additional free-of-charge
esd CAN tools for Windows offer efficient setup and analysis of CAN applications and networks.
The firmware can be updated from the PC.
CAN-USB/Micro Manual • Doc. No.: C.2068.21 / ev. 1.2 Page 7 of 23
C
A
N
B
U
S
CAN USB Data
Microcontroller
USB PWR
DSUB9
Male Contacts
CiA
®
Pin Assignment
Power
Supply
3 3 V
Physical
CAN Layer
ISO11898-2
LED
green
LED
red
DSUB9 Enclosure
USB Type A
Connector
1 0 m USB Cable

View of the Connectors
2. View of the Connectors
Figure 2 Connectors of CAN-USB/Micro
Page 8 of 23 Manual • Doc. No.: C.2068.21 / ev. 1.2 CAN-USB/Micro

Hardware Installation
3. Hardware Installation
Read the safety instructions at the beginning of this document carefully, before
you start with the hardware installation!
Procedure
1. Connect the USB connector of the CAN-USB/Micro to the USB bus of the PC.
2. Connect the 9-pin male DSUB connector to the CAN bus.
Please remember that the CAN bus has to be terminated at both ends. esd offers
T-connectors and terminators. Additionally, the CAN-GND signal has to be grounded at
exactly one point in the CAN network. Therefore the CAN termination connectors have got a
grounding contact.
A CAN device whose CAN interface is not electrically isolated (like the CAN-USB/Micro)
corresponds to the grounding of the CAN-GND.
3. End of hardware installation.
4. The software installation is described in the manual
“NTCAN, Part 2: Installation, Configuration and Firmware Update, Installation Guide”
CAN-USB/Micro Manual • Doc. No.: C.2068.21 / ev. 1.2 Page 9 of 23

LED Description
4. LED Description
Figure 3 LEDs CAN-USB/Micro
Name Colour Description
Activity green
on USB module is enumerated (a node address is assigned to
the USB module)
flash off receives CAN telegrams or USB commands
off not working
CAN-Error red on
CAN-Bus-off,
CAN-Error-passive or
CAN-Controller-Warn
off CAN bus OK, (CAN-Error-active)
Page 10 of 23 Manual • Doc. No.: C.2068.21 / ev. 1.2 CAN-USB/Micro

Summary of Technical Data
5. Summary of Technical Data
5.1 General Technical Data
Temperature range 0...50 °C ambient temperature
Humidity 90% non-condensing
Power supply via USB:
nominal voltage:
current consumption
(without CAN traffic):
5 V +5 % /-12%
typical at 5 V : 50 mA
Connectors USB - USB 2.0 interface (USB type A plug, X100)
CAN - CAN interface (9-pin DSUB, male connector, X200)
Dimensions cable length 1.0 m including connectors,
DSUB9: 35 mm x 15 mm x 45 mm
IP rating IP20
Weight approx. 100 g
5.2 USB Interface
Number 1x USB
Controller integrated in A M-Cortex-M3 STM32F105, 32-bit, 72 MHz
USB interface USB 2.0, Full-Speed, 12 Mbit/s
Connector USB type A plug
5.3 CAN Interface
Number of CAN
interfaces 1x integrated in DSUB9-enclosure
CAN controller integrated in A M-Cortex-M3 STM32F105, 32 bit, 72 MHz
CAN protocol ISO 11898-1
Physical Layer CAN High speed interface according to ISO 11898-2,
bit rate up to 1 Mbit/s
Electrical isolation none
Bus termination has to be set externally
Connector DSUB9, according to CiA 303-1
CAN-USB/Micro Manual • Doc. No.: C.2068.21 / ev. 1.2 Page 11 of 23

Summary of Technical Data
5.4 Software Support
Software drivers for Windows® 2K/XP/Vista/7/8 (32/64 bit) are included in delivery.
Linux® kernel ≥ 2.6 is supported via Linux CAN (SocketCAN) and NTCAN wrapper library. Drivers
for other operating systems are available on request.
Libraries for the higher layer protocols CANopen and J1939 are available. Additional free-of-charge
esd CAN tools for Windows offer efficient setup and analysis of CAN applications and networks.
The firmware can be updated from the PC. Updates are available on the esd website www.esd.eu.
5.5 Firmware License
The CAN-USB/Micro uses the open source Free TOSTM (www.freertos.org) operating system.
The source code of the operating system is published in terms of the GNU Public License (GPL).
For the full license text please see esd's “3rd party lisensor notice” document that is part of the
product's documentation on the enclosed CD.
Page 12 of 23 Manual • Doc. No.: C.2068.21 / ev. 1.2 CAN-USB/Micro

Connector Assignment
6. Connector Assignment
6.1 USB
Device connector: USB connector type A
Pin Position
Pin Assignment
Pin Signal
1VBUS
2 D-
3 D+
4 GND
Signal Description
VBUS... +5 V power supply voltage
D+, D-... USB signal lines Data+, Data-
GND... eference potential
CAN-USB/Micro Manual • Doc. No.: C.2068.21 / ev. 1.2 Page 13 of 23
1 2 3 4

Connector Assignment
6.2 CAN
Device connector: 9-pin DSUB connector, male
Pin Position
Pin Assignment
Signal Pin Signal
1
reserved
reserved
6
2
CAN_L
CAN_H
7
3
CAN_GND
reserved
8
4
reserved
reserved
9
5CAN_GND
(CAN_Shield)
Signal Description
CAN_L, CAN_H ... CAN signal lines
CAN_GND ... reference potential of the local CAN physical layer
CAN_GND (CAN_Shield) ... CAN_Shield is connected to shield of the USB wire and to GND
reserved ... reserved for future applications, do not connect!
Page 14 of 23 Manual • Doc. No.: C.2068.21 / ev. 1.2 CAN-USB/Micro
12345
6789

Correctly Wiring of CAN Networks
7. Correctly Wiring of CAN Networks
For the CAN wiring all applicable rules and regulations (EC, DIN), e.g. regarding electromagnetic
compatibility, security distances, cable cross-section or material, have to be met.
7.1 General Rules
Note
esd only grants the compliance with directive 2004/108/EC, if the CAN wiring is carried
out with at least single shielded twisted pair cables that match the requirements of ISO
11898-2.
The following general rules for the CAN wiring must be followed:
1A cable type with a wave impedance of about 120 Ω ±10% with an adequate wire cross-section
(0.22 mm²) has to be used. The voltage drop over the wire has to be considered!
2For residential, commercial and light industrial environment use at least a two-wire CAN cable. Connect
•
•
the two twisted wires to the data signals (CAN_H, CAN_L) and
the cable shield to the reference potential (CAN_GND)!
3The reference potential CAN_GND has to be connected to the functional earth (FE) at exactly one
point.
The CAN-USB/Micro connects CAN_GND and FE, so no further connection should be made!
4A CAN net 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 at GND)!
5Keep cable stubs as short as possible (l < 0.3 m)!
6Select a working combination of bit rate and cable length.
7Keep away cables from disturbing sources. If this cannot be avoided, double shielded wires are
recommended.
Figure. 4 CAN wiring with single shielded twisted pair cables
CAN-USB/Micro Manual • Doc. No.: C.2068.21 / ev. 1.2 Page 15 of 23
CAN GND
CAN_H
CAN_GND
n c
n c
n c
n c
CAN_L 1
4
5
6
7
9
2
3
8
9
1
4
5
6
7
3
8
2
earth (FE)
CAN_L
CAN_H
CAN_GND
Single shielded
twisted pair cable
(two-wire cable,
x 2x 0.22mm²)
CAN_GND
(at wire shield)
Wire Layout
Signal assignment of single shielded twisted pair cable
with earth and termination
n c
n c
n c
n c
n c
n c
n c
n c
n c
n c
n c
n c
n c
n c
n c = not connected
DSUB9 connector
(female or male)
pin designation
connector case connector case
DSUB9 connector
(female or male)
pin designation
AN wire with connectors

Correctly Wiring of CAN Networks
7.2 Cabling
●For devices which have only one CAN connector per net use T-connector and stub (shorter
than 0.3 m) (available as accessory).
Figure. 5 Example for proper wiring with single shielded single twisted pair wires
7.3 Termination
●If the used CAN interface is not equipped with an integrated CAN termination and it is at an
end of the bus, use external termination plugs.
●9-pin DSUB-termination connectors with male and female contacts and earth terminal are
available as accessories.
Page 16 of 23 Manual • Doc. No.: C.2068.21 / ev. 1.2 CAN-USB/Micro

Correctly Wiring of CAN Networks
7.4 Earthing
●CAN_GND has to be connected to the functional earth potential (FE) at exactly one point
of the network!
●Each CAN interface with electrical connection to earth potential like the CAN-USB/Micro
acts as an earthing point. For this reason do not connect more than one CAN device with
electrical connection to earth potential!
●Earthing can e.g. be made at a connector/T-connector.
7.5 Bus Length
●Optical couplers are delaying the CAN signals. esd modules typically reach a wire length of
37 m at 1 Mbit/s within a closed net without impedance disturbances like e.g. cable stubs
>> 0.3 m.
Bit rate
[Kbits/s]
Typical values of reachable
wire length with esd
interface lmax [m]
CiA recommendations
(07/95) for reachable wire
lengths lmin [m]
1000
800
666.6
500
333.3
250
166
125
100
66.6
50
33.3
20
12.5
10
37
59
80
130
180
270
420
570
710
1000
1400
2000
3600
5400
7300
25
50
-
100
-
250
-
500
650
-
1000
-
2500
-
5000
Table 1 ecommended cable lengths at typical bit rates (with esd-CAN interfaces)
Note
Please note the recommendations according to ISO 11898 for the selection of the cross
section of the wire depending of the wire length.
CAN-USB/Micro Manual • Doc. No.: C.2068.21 / ev. 1.2 Page 17 of 23

Correctly Wiring of CAN Networks
7.6 Examples for CAN Cables
Manufacturer Type of wire
U.I. LAPP GmbH
Schulze-Delitzsch-Straße 25
70565 Stuttgart
Germany
www.lappkabel.de
e.g.
UNIT ONIC ®-BUS CAN UL/CSA (1x 2x 0.22)
(UL/CSA approved) Part No.: 2170260
UNIT ONIC ®-BUS-FD P CAN UL/CSA (1x 2x 0.25)
(UL/CSA approved) Part No.: 2170272
ConCab GmbH
Äußerer Eichwald
74535 Mainhardt
Germany
www.concab.de
e. g.
BUS-PVC-C (1x 2x 0,22 mm²) Order No.: 93 022 016 (UL appr.)
BUS-Schleppflex-PU -C (1x 2x 0,25 mm²) Order No.: 94 025 016 (UL appr.)
Note
Configured CAN cables can be ordered from esd.
Page 18 of 23 Manual • Doc. No.: C.2068.21 / ev. 1.2 CAN-USB/Micro

CAN-Bus Troubleshooting Guide
8. CAN-Bus Troubleshooting Guide
The CAN Troubleshooting Guide is a guide to find and eliminate the most frequent hardware-error
causes in the wiring of CAN-networks.
Figure 6 Simplified diagram of a CAN network
8.1 Termination
The termination is used to match impedance of a node to the impedance of the transmission line
being used. When impedance is mismatched, the transmitted signal is not completely absorbed by
the load and a portion is reflected back into the transmission line. If the source, transmission line
and load impedance are equal these reflections are eliminated. This test measures the series
resistance of the CAN data pair conductors and the attached terminating resistors.
To test it, please
1. Turn off all power supplies of the attached CAN nodes.
2. Measure the DC resistance between CAN_H and CAN_L at the ends of
the network (see figure above) and at the centre of the network (if the network cable
consists of more than one line section).
The measured value should be between 50 Ω and 70 Ω. The measured value should be nearly the
same at each point of the network.
If the value is below 50 Ω, please make sure that:
- there is no short circuit between CAN_H and CAN_L wiring
- there are not more than two terminating resistors
- the nodes do not have faulty transceivers.
If the value is higher than 70 Ω, please make sure that:
- there are no open circuits in CAN_H or CAN_L wiring
- your bus system has two terminating resistors (one at each end) and that they are 120 Ω
each.
CAN-USB/Micro Manual • Doc. No.: C.2068.21 / ev. 1.2 Page 19 of 23
120

CAN_H
CAN_GND
CAN_L
CAN_L
CAN_H
CAN_GND
V
120 
23
1
V
1


CAN-Bus Troubleshooting Guide
8.2 Electrical Grounding
The CAN_GND of the CAN network has to be connected to the functional earth potential (FE) at
only one point. This test will indicate if the CAN_GND is grounded in several places.
To test it, please
1.
2.
3.
Disconnect the CAN_GND from the
earth potential (FE).
Measure the DC resistance
between CAN_GND and earth
potential (see figure on the right).
Connect CAN_GND to earth potential.
Figure 7 Simplified schematic diagram of ground test measurement
The resistance should be higher than 1 MΩ. If it is lower, please search for additional grounding of
the CAN_GND wires.
8.3 Short Circuit in CAN Wiring
A CAN bus might possibly still be able to transmit data if there is a short circuit between CAN_GND
and CAN_L, but the error rate will increase strongly. Make sure that there is no short circuit
between CAN_GND and CAN_L!
8.4 CAN_H/CAN_L-Voltage
Each node contains a CAN transceiver that outputs differential signals. When the network
communication is idle the CAN_H and CAN_L voltages are approximately 2.5 volts. Faulty
transceivers can cause the idle voltages to vary and disrupt network communication.
To test for faulty transceivers, please
1. Turn on all supplies.
2. Stop all network communication.
3. Measure the DC voltage between CAN_H and GND
(see figure above).
4. Measure the DC voltage between CAN_L and GND
(see figure above).
Page 20 of 23 Manual • Doc. No.: C.2068.21 / ev. 1.2 CAN-USB/Micro
2
3
>1M 
CAN_H
CAN_GND
CAN_L

functional earth
(FE)

CAN-Bus Troubleshooting Guide
Normally the voltage should be between 2.0 V and 4.0 V.
If it is lower than 2.0 V or higher than 4.0 V, it is possible that one or more nodes have faulty
transceivers. For a voltage lower than 2.0 V please check CAN_H and CAN_L conductors for
continuity. For a voltage higher than 4.0 V, please check for excessive voltage.
To find the node with a faulty transceiver please test the CAN transceiver resistance (see below).
8.5 CAN Transceiver Resistance Test
CAN transceivers have one circuit that controls CAN_H and another circuit that controls CAN_L.
Experience has shown that electrical damage to one or both of the circuits may increase the
leakage current in these circuits.
To measure the current leakage through the CAN circuits, please use an resistance measuring
device and:
1. Switch off the node and disconnect it from the network
(see figure below).
2. Measure the DC resistance between CAN_H and CAN_GND
(see figure below).
3. Measure the DC resistance between CAN_L and CAN_GND
(see figure below).
The measured resistance has to be about 500 kΩ for each signal. If it is much lower, the CAN
transceiver it is probably faulty.
Another sign for a faulty transceiver is a very high deviation between the two measured input
resistance (>> 200%).
Figure 8 Measuring the internal resistance of CAN transceivers
CAN-USB/Micro Manual • Doc. No.: C.2068.21 / ev. 1.2 Page 21 of 23
4
5
6
CAN_H
CAN_GND
CAN_L
5 6
4
4
Power

CAN
transceiver
disconnect
power!
disconnect
CAN!
CAN node