CAN Interface

This interface is the connection to a processor module with onboard CAN e.g. PM56xx-2ETH.

Interface socket COMBICON, 5-pin, female, removable plug with spring terminals
Transmission standard ISO 11898, potential-free
Transmission protocol CANOPEN (CAN), 1 Mbaud max.
Transfer rate (baud rate) 50 kbit/s, 100 kbit/s, 125 kbit/s, 250 kbit/s, 500 kbit/s, 800 kbit/s and 1 Mbit/s,

Pin Assignment

Interface Pin Signal Description
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Terminal block removed

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Terminal block inserted

 1 CAN_GND CAN reference potential
2 CAN_L Bus line, receive/transmit line, LOW
3 CAN_SHLD Shield of the bus line
4 CAN_H Bus line, receive/transmit line, HIGH
5 NC Not connected

Attention

:strong:Unused connector!

Make sure that the terminal block is always connected to the terminal base, even if you do not use the interface.

Bus Length

The maximum possible bus length of a CAN network depends on bit rate (transmission rate) and cable type. The sum of all bus segments must not exceed the maximum bus length

Bit Rate (speed) Bus Length
1 Mbit/s 40 m
800 kbit/s 50 m
500 kbit/s 100 m
250 kbit/s 250 m
125 kbit/s 500 m
   
50 kbit/s 1000 m
   
   

Types of Bus Cables

Only bus cables with characteristics as recommended in ISO 11898 are to be used. The requirements for the bus cables depend on the length of the bus segment. See : CANOPEN Field Bus

Bus Terminating Resistors

Both ends of the CAN bus have to be terminated with a 120 Ω (≥ 1/4 W, ≤ 5 %) bus terminating resistor, to minimize signal reflection. The bus terminating resistor should be connected directly at the bus connector between the CAN signals (CAN_H and CAN_L). See : CANOPEN Field Bus