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Contemporary Research
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TD960801-0MC
User Manual
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Contemporary Research TD960801-0MC User Manual

EXTEND-A-BUS
A Line of Fieldbus Extenders for DeviceNet
for
User Manual
#TD960801-0MC

Trademarks

Copyright

© Copyright April 1999-2002 by Contemporary Control Systems, Inc. All rights reserved. No part of this publication may be reproduced, transmitted, transcribed, stored in a retrieval system, or translated into any language or computer language, in any form or by any means, electronic, mechanical, magnetic, optical, chemical, manual, or otherwise, without the prior written permission of:
Contemporary Control Systems, Inc. 2431 Curtiss Street Downers Grove, Illinois 60515 USA Tel: +1-630-963-7070 Fax: +1-630-963-0109 E-mail: info@ccontrols.com WWW: http://www.ccontrols.com
Contemporary Controls Ltd Sovereign Court Two University of Warwick Science Park Sir William Lyons Road Coventry CV4 7EZ UK Tel: +44 (0)24 7641 3786 Fax: +44 (0)24 7641 3923 E-mail: info@ccontrols.co.uk

Disclaimer

Contemporary Control Systems, Inc. reserves the right to make changes in the specifications of the product described within this manual at any time without notice and without obligation of Contemporary Control Systems, Inc. to notify any person of such revision or change.
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Contents

Chapter 1 Introduction......................................................... 1
1.1 Description................................................1
1.2 Features..................................................... 2
1.3 Specifications ............................................ 2
1.4 Port Specifications .................................... 3
1.5 Ordering Information ................................ 4
Chapter 2 Installation........................................................... 5
2.1 Introduction ...............................................5
2.2 Electromagnetic Compliance..................... 5
2.3 Mounting the EXTEND-A-BUS...............6
2.4 Powering the EXTEND-A-BUS ............... 6
2.5 Connecting to the CAN Port ..................... 9
2.6 Connecting to the Backbone Port ............ 12
Chapter 3 Operation .......................................................... 19
3.1 CAN Communications ............................ 19
3.2 Theory of Operation................................ 20
3.3 System Considerations ............................ 23
3.4 LED Indicators........................................ 25
Chapter 4 Service ............................................................... 27
W arranty............................................................. 27
T echnical Support............................................... 28
Warranty Repair ................................................. 28
Non-W arranty Repair .........................................29
Returning Products for Repair............................ 29
Appendices
Appendix A—Permissible Segment Lengths ...... 31
Appendix B—Declaration of Conformity........... 34
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List of Figures

Figure 2-1 DC Powered........................................................ 7
Figure 2-2 Redundant DC Powered...................................... 8
Figure 2-3 AC Powered........................................................ 8
Figure 2-4 AC Powered with Battery Backup ...................... 9
Figure 2-5 CAN Port Connector Assignments ................... 10
Figure 2-6 Data Rate Switch .............................................. 11
Figure 2-7 Appropriate terminators are required
at the ends of both the coaxial cable backbone
and DeviceNet subnets......................................13
Figure 2-8 A maximum of eight EXTEND-A-BUSes can .....
occupy one coaxial backbone segment before an..
active hub is required ........................................ 14
Figure 2-9 A 62.5/125 µm duplex fiber optic cable is
used on the -FOG model up to a maximum of
1830 meters....................................................... 15
Figure 2-10 By using two AI3-CXS hubs, a
distributed star topology is achieved .................17
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1 Introduction

1.1 Description

The EXTEND-A-BUS for DeviceNet series of fieldbus extenders enable the geographic expansion of CAN-based device networks such as DeviceNet by linking individual DeviceNet subnets together into a single larger network.
The medium arbitration method used by DeviceNet is intolerant of excessive signal delay . Since cable length introduces delay , DeviceNet networks tend to be distance limited. Repeaters are ineffective in extending distances since they introduce additional delay . On the other hand, fieldbus extenders like EXTEND-A­BUS solve the problem by segmenting a single DeviceNet network into manageable subnets.
EXTEND-A-BUS interconnects two physically separated but similar networks using a different interconnecting medium. Thus, a pair is required to interconnect two networks (or subnets) the way two modems are used on leased phone lines.
Utilizing ARCNET as the high-speed deterministic interconnecting medium, the EXTEND-A-BUS captures DeviceNet traffic and replicates it to the receiving device. The receiving device removes DeviceNet data and rebroadcasts the data to its attached DeviceNet subnet. EXTEND-A-BUS does not filter out DeviceNet identifiers or MAC addresses, so DeviceNet messages are rebroadcast unmodified.

Application Information

Each EXTEND-A-BUS creates a DeviceNet subnet and a minimum of two EXTEND-A-BUSes is required to establish a network. The data rate on each subnet can be different from the other subnets. DeviceNet identifiers or MAC ID checks are replicated on all subnets. EXTEND-A-BUS pairs are best viewed as an extension cord. Each EXTEND-A-BUS does not consume a permanent MAC ID and, therefore, is transparent to the network.
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Extending the Interconnecting Medium or Backbone

The backbone side of the EXTEND-A-BUS must comply with standard ARCNET cabling rules. Companion AI ARCNET active hubs are available for extending the backbone cabling up to 6 km using coaxial cabling and ten active hubs. When using a fiber optic backbone, a maximum of 4.8 km can be achieved requiring two active hubs. Hubs are cascaded to reach the required distance.

1.2 Features

• Extends the length of DeviceNet networks up to 6 km
• Fully DeviceNet compliant
• Fiber optic or coaxial cabling
• Star, bus or distributed star topology
• Variable data rate up to 500 kbps
• Low voltage AC or DC powered
• Panel-mount enclosure

1.3 Specifications

Electrical

DC AC Input voltage: 10–36 volts 8–24 volts Input power: 4 watts 4VA Input frequency: N/A 47-63 Hz

Power Options

– DC powered – Redundant powered – AC powered – AC powered with battery backup
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Environmental

Operating: 0°C to 60°C Storage: -40°C to +85°C

Functional

Data latency: 1.2 ms typical per EXTEND-A-BUS pair

Regulatory Compliance

FCC Part 15 Class A CE Mark

1.4 Port Specifications

CAN Port
Compliance DeviceNet
Volume I, Release 2.0
Data Rate 125 kbps, 250 kbps, 500 kbps select-
able or
Autobaud 125 kbps, 250 kbps, 500 kbps LEDs CAN status:
Module status/network status
T ransceivers Optically isolated 82C251 Cable DeviceNet Thick Connectors 5 position Open-pluggable Maximum segment 125 kbps: 500 meters (1640 ft) or subnet distance 250 kbps: 250 meters (820 ft)
500 kbps: 100 meters (328 ft)
Maximum number of nodes per segment 64 Terminating resistor 121 ohms
Backbone Port
Compliance ARCNET
ANSI/ATA 878.1
Data Rate 2.5 Mbps
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LEDs Link status:
Reconfiguration status/activity status
T ransceivers -CXB model: transformer coupled
-FOG model: 850 nm duplex fiber optic
Cable -CXB model: RG-62/u coaxial
-FOG model: 62.5/125 µm duplex fiber optic
Connectors -CXB model: BNC
-FOG model: ST
Maximum segment -CXB model: 305 meters (1000 ft) or subnet distance -FOG model: 1830 meters (6000 ft)
(optical power budget 10.4dB)
Maximum number -CXB model: 8 of nodes per segment -FOG model: N/A Terminating resistor -CXB model: 93 ohms
-FOG model: N/A

1.5 Ordering Information

The EXTEND-A-BUS series is available in several configurations depending upon the application and cable media supported.
EXTEND-A-BUSes:
EB/DNET-CXB EXTEND-A-BUS with coaxial bus backbone EB/DNET-FOG EXTEND-A-BUS with fiber optic backbone
Accessories:
AI-XFMR W all-mount transformer 120 VAC (nom) AI-XFMR-E Wall-mount transformer 240 VAC (nom) AI-DIN DIN-rail mounting kit BNC-T BNC “T” connector BNC-TER 93-ohm BNC terminator
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2 Installation

2.1 Introduction

The EXTEND-A-BUS series is intended to be panel mounted into an industrial enclosure or into a wiring closet. T wo #8 pan head screws (not provided) are required for mounting. Optionally , the bridge can be mounted on a DIN rail by purchasing a DIN rail mounting kit.

2.2. Electromagnetic Compliance

The EXTEND-A-BUS series complies with Class A radiated and conducted emissions as defined by FCC part 15 and EN55022. This equipment is intended for use in non-residential areas. Refer to the following notices in regard to the location of the installed equipment.
Note: This equipment has been tested and found to comply with the limits for a Class A digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a commercial environment. This equipment generates, uses, and can radiate radio frequency energy and, if not installed and used in accordance with the instruction manual, may cause harmful interference to radio communications. Operation of this equipment in a residential area is likely to cause harmful interference in which case the user will be required to correct the interference at his own expense.
W arning This is a Class A product as defined in EN55022. In a
domestic environment this product may cause radio interference in which case the user may be required to take adequate measures.
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The EXTEND-A-BUS has been tested to EN50082 Generic Immunity Standard–Industrial Environment. This standard identifies a series of tests requiring the equipment to perform to a particular level during or after the execution of the tests. The three classes of performance are defined by CCSI as follows:
Class A - Normal operation, however, occasional reconfigurations may occur or throughput may be reduced due to an error recovery algorithm by the ARCNET data link level protocol.
Class B - Throughput reduced to zero and continuous reconfigurations occur. Normal operation resumed after offending signal removed.
Class C - Complete loss of function. Unit resets and normal operation restored without human intervention.
At no time did the EXTEND-A-BUS fail to return to normal operation or become unsafe during the execution of these tests.
A copy of the Declaration of Conformity is in the appendix.

2.3 Mounting the EXTEND-A-BUS

The EXTEND-A-BUS is intended for mounting onto a vertical panel within an industrial control enclosure. T wo #8 screws can be used for mounting the EXTEND-A-BUS in a vertical orientation. Refer to the mechanical specifications for details.
T o mount the EXTEND-A-BUS onto a DIN rail, an optional DIN rail mounting clip (AI-DIN) must be purchased and installed on the rear of the EXTEND-A-BUS. Once the clip is mounted to the EXTEND-A-BUS, the EXTEND-A-BUS can be snapped onto the DIN rail.

2.4 Powering the EXTEND-A-BUS

The EXTEND-A-BUS requires either low voltage AC or DC power in order to operate. Consult the specifications for power requirements. Power is provided to a four pin removable keyed
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connector . There are several methods for providing power . These methods are DC powered, redundant DC powered, AC powered and AC powered with battery backup.

2.4.1 DC Powered

Make connections as shown in Figure 2-1. The EXTEND-A­BUS incorporates a DC-DC converter that accepts a wide voltage range (10–36 VDC) and converts the voltage for internal use. Input current varies with input voltage so it is important to size the power conductors accordingly . Input power to the EXTEND-A-BUS maximizes at 4 watts; therefore, at 10 VDC, the input current is approximately 400 ma. The ground connection to the EXTEND-A-BUS is connected to chassis within the EXTEND-A-BUS. The input connections are reverse voltage protected.
Figure 2-1. DC Power ed

2.4.2 Redundant DC Power ed

Redundant diode isolated DC power inputs are provided on the EXTEND-A-BUS for those applications in which there is a concern that the EXTEND-A-BUS remain operational in the event of a primary power failure. Make connections as shown in Figure 2-2. Each power supply source must be sized for the full 4-watt load of the EXTEND-A-BUS. Do not assume that input currents will be balanced from the two supplies.
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Figure 2-2. Redundant DC Powered

2.4.3 AC Powered

If only AC power is available, the EXTEND-A-BUS can be powered by the secondary of a low voltage transformer whose primary is connected to the AC mains. The secondary voltage must be in the range of 8 to 24 VAC, 47–63 Hz with the capability of delivering up to 4 VA of apparent power. The secondary of the transformer must not be grounded. For convenience, two auxiliary power supplies are available:
• AI-XFMR for 120 VAC primary power
• AI-XFMR-E for 240 VAC primary power
Reference Figure 2-3.
Figure 2-3. AC Power ed
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