Westrn Reserve Controls
WRC-CANR-DF-DN and –SM User’s Manual
PUB 14.1
Revision 4.03
1
1. Overview
The WRC-CANR-DF Fiber Optic CAN Bus Extenders convert a copper cable medium CAN-Bus
network to a fiber optic medium. The WRC-CANR-DF-DN uses multimode fiber optic cable, while the
WRC-CANR-DF-SM uses single-mode fiber optic cable. Both are always used in pairs with a length of
fiber media in between. The primary purposes of this type of configuration is to extend the maximum
length defined for one continuous network cable bus up to 2.2km (for multimode with WRC-CANR-DF-
DN) or 12km (for single-mode with WRC-CANR-DF-SM) and to provide network protection from external,
high-energy electrical interference, such as lightning storms, arc welders, etc. They can be connected in a
bus trunk line or drop line.
A WRC-CANR can be used for quite a number of helpful purposes, including
•
To provide an electrically-isolated fiber transmission segment to your CAN bus for more
secure network in high-energy environmental conditions
•
to extend the network beyond its absolute maximum at the slowest speed
•
to implement a longer network for a given baud rate (e.g., pushing a 500K baud network
beyond 100 m for DeviceNet)
•
to provide higher speed baud rates for a given network length
•
to extend the length of the drop cable (e.g., longer drops than 6 m for DeviceNet)
•
to provide 2600V electrical isolation between the 2 sub-nets
•
to create a unique network topology instead of a conventional bus structure, such as a
star configuration
The Extenders are transparent to the other nodes on the bus. They receive and actively re-
transmit (store-and-forward) each message received at either side of the network without interpreting the
message or acting upon it. The Fiber Extenders perform all appropriate CAN Bus arbitration on the copper
bus as it re-transmits the message.
The WRC-CANR-DF-DN and WRC-CANR-DF-SM are members of WRC’s family of products that
extend the system communications lengths for DeviceNet, CANopen, SDS (Smart Distributed System),
J1939 and other CAN, V2.0, Part A or Part B, serial bus systems. By allowing the user to extend the bus
length for any given speed, they assist the user in cost-effectively implementing I/O or other nodes on
these buses at remote locations that would be more difficult or more expensive to do otherwise.
The unit derives its power through the copper network connector on Side A.
1.1. Series IV Specific Features
The Series IV WRC-CANR provides enhancements over previous the previous Series III
products, including:
*
Single Mode Fiber Cable Option is now available.
