Physical Layer
CANbus
Unitronics’ CANbus runs on the same physical layer as
A.B.’s Device Net, but uses a different protocols.
A CANbus network can include up to 63 PLCs and mix
different models of M90/91as well as Vision.
The CANbus port can be used in 4 ways:
•
•
•
•
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To connect a net of up to 63 units to a PC
To connect a net of up to 64 units one to the other
To exchange data with 3rd party device
To “see” controllers via PC
CAN bus wiring Specifications
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CAN bus Cable Lookout
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Networking CANbus
Methods of data exchange:
PLC to PLC
 CANbus ISC (Inter-Save Connection)
Data is broadcast over the CANbus network via system operands,
where each unit can read information from up to 8 other PLCs in the
network.
 UniCAN DataCom
This enables a PLC in the CANbus network to exchange data
with up to: 60 other networked PLCs .
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Networking CANbus
PLC to 3rd Party Device
CANopen
Supports data communication with remote devices
according to the CANopen standard.
CANbus , Layer 2
Enables Vision controllers to send and receive data with remote devices
that support CANbus protocol.
J1939
Automotive CAN. Enables Vision controllers to communicate on the
automotive Can Network.
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CANbus Network to PC
Unit ID 1
Bridge
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Unit ID 2
Unit ID 3
CANbus ISC
CANbus ISC is a multi-master protocol.
Via the CANbus port, you can :
• Network up to 63/64 controllers
• Each networked PLC broadcasts specific data to the network
• 16 System Bits (SB 200 to SB 215)
• 16 Inputs (I 0 to I 15)
• 2 System Integers (SI 200 and SI 201)
• Each unit can read information from up to 8 other
controllers in the network
• Supported both by M90, M91 and Vision controllers
• Mixed networks possible
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Communication UniCAN
Multi-Master protocol
• Up to 60 units in network
• Via UniCAN, a Unitronics'
PLC can exchange data
with up to 60 other
networked PLCs
• UniCAN can send up to 32
messages, each containing
16 integer values, totaling
512 MI register values
during a single program scan
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UniCAN
Assign each networked controller a unique Unit ID
Number and initialize the CANbus port to UniCAN .
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UniCAN
Send Registers
You can send a vector
of values up to 16
integers long in a
single Send function.
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Broadcast
Use Broadcast to send an MB and an MI value to all controllers
in the UniCAN network.
Source controller ID# 3 contains 123 in MI 50, and has MB 50 ON :
all controllers in the network will have 3 written into SI 201
123 written into SI 200, and SB 200 will be turned ON.
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Check Alive Signal
Each 0.5 seconds, a unit sends an 'Alive'
signal to the CANbus network.
The Check Alive Signal function receives the
signal.
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Message Arrived
When a message arrives from the networked
unit whose ID # is given in the function, the
Status MB turns ON.
When the message is received, the
corresponding bit in SIs-240-243, which provide
a bitmap of all units in the UniCAN network,
turns OFF.
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Thank You !
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