User`s manual

Western Reserve Controls WRC-CANR-DF-DN User’s Manual
PUB 14.1 Series 3
2
• Jumper-selectable terminating resistor on-board the CANX
• Increased message internal buffers – Automatic Memory Technology (AMT) operation
• Eliminates the distinction between WRC’s earlier version Type 1 and Type 2 CANR’s
1.2. Features
The WRC-CANR-DF-DN has the following features:
• Extends CAN-Bus cable lengths - trunk line or drop lines
• Expands the usable applications for CAN-Bus systems
• Allows operation at higher speeds for specific distances
• Provides superior electrical interference protection to copper cables
• Operates at 125K, 250K, 500K and 1M baud
• Switch-selectable Autobaud or fixed baud rate operation
• Automatic speed selection - no configuration required
• Isolates the two sections of the copper bus
• Transparent to the Master and Slave devices on the bus
• No address selection needed
• No configuration parameters
• DeviceNet; SDS; CAN, V2.0, Part A and Part B compatible
• Powered from the 24Vdc supplied by bus network or the user
• Sealed NEMA-4X enclosure
• Standard round, mini-style connector with male pins for copper cable
• Standard Fiber Optic ST female connector, 62.5/125um technology
• Standard CAN chips manage bus error detection
• Standard CAN chips handle message bus contention
• Less than 100 µsec latency
• Jumper-selectable termination built in on cable side
• 4 bi-color (red/green) status LEDs
• 2 green fiber transmit and receive LEDs
1.3. Basic Operation
Two CANR-DF units are required for each application – both units are identical. It does not matter
which is placed in which position with respect to the network topology or other devices on the network.
There are two bus connections for each CANR-DF, referred to as the Copper Cable Network Side
(Side A) and Fiber Cable Network Side (Side B). The CAN Bus copper cable is connected to side A of the
CANR-DF receives its power from side A.
Figure 1-1 shows a typical application.
Whenever a message is transmitted on the Bus to which CANR-DF is connected, CANR-DF
receives the message on the side where it was initiated and performs a store-and-forward of the message to
the other side. This action is performed in each direction and is performed for any valid CAN message
independent of who generated it or to whom it is intended.
There is approximately a 75µsec propagation delay of the message through the CANR-DF.
The CANR-DF is not addressed as a specific device on the Bus and cannot be interrogated by other
nodes. It is transparent to all other nodes on the bus.