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CANopen: The physics.

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Presentation on theme: "CANopen: The physics."— Presentation transcript:

1 CANopen: The physics

2 What is contained in a CAN node ?
CAN-Controller CAN-Tranceiver CAN

3 Practical values for the trunk length
kbit/s 1000 800 500 250 125 The maximum achievable bus line length in a CAN network is determined essentially by the following physical effects: the loop delays of the connected bus nodes and the delay of the bus lines the differences in bit time quantum length due to the relative oscillator tolerance between nodes the signal amplitude drop due to the series resistance of the bus cable and the input resistance of bus nodes The shown practical bus length can be reached with ISO compliant transceivers and standard bus line cables. Please note there are no opto couplers considered. 62,5 20 10 /../ Trunk length in m

4 CANopen specifications according to CiA
DC parameters for CANopen networks for less than 64 nodes Cable type Maximum trunk length for different cable types and node numbers CAN limits The CiA (CAN in automation) specifies guidance values for different cable characteristics. In those papers there is also a formula for calculating the maximum length of unterminated stubs which involves values like the Resynchronization time. Basically stubs should just be avoided. Maximum trunk length [m] (1) Maximum truk length [m] (2) (1) Safety margin factor of 0.2 (2) Safety margin factor of 0.1

5 Our cable recommendation

6 Caution: Please regard the polarity when connecting!
ISO Network Set-up node node n CAN_H The ISO standard assumes the network wiring technology to be close to a single line structure in order to minimize reflection effects on the bus line. The bus lines have to be terminated by resistors at both ends. CAN Bus Line 120  120  CAN_L Caution: Please regard the polarity when connecting!

7 Hardeware installation of a CAN - XION Gateway
Bit Rate (10kbit/s - 1Mbit/s) 1 2 3 4 „0“,Off „1“,On Accept configuration press for 2 secs! Address switches (0-127) 7 9 1 F 4 C 2 3 5 6 A B D E High Low Attention! When saving the XI/ON configuration all CANopen objects, whose parameter values deviate from the default values must be parametrized anew. The complete Station parametrization must then be loaded into the XI/ON station again. 8 8 <=> 12 Hex => Station address 18 (Dez) Caution: Address „0“ must not be used!

8 Baud rates DIP switch Switch (position) reserved

9 9-p in Sub Connector DIN 41652 Pin Signal Description 1 - Reserved
CAN_L CAN_L bus line dominant low CAN_GND CAN Ground Reserved (CAN_SHLD) Optional CAN Shield GND Optional Ground CAN_H CAN_H bus line dominant high Reserved (CAN_V+) Optional CAN external positive supply The physical medium for CANopen devices is a differentially driven two-wire bus line with common return according to ISO The CiA DRP CANopen recommendation defines the pinning of the 9-pin D-sub connector (DIN or corresponding international standard), the 5-pin mini style connector, the open style connector, the multi-pole connector, and other connectors. The 9-pin D-Sub connector pinning complies to CiA DS-102. Quelle: CIA

10 Mini-style Connector : ANSI/B93.55M-1981 Quelle: CIA

11 Open-style Connector Quelle: CIA

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