B&R Industries Provit 5000, Руководство пользователя

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352 Provit 5000 User’s Manual
Technical Appendix • CAN Bus
The buffer duration of the battery is at least 4 years (at 50°C, 8,5 µA of the supplied components
and a self discharge of 40%)
3. CAN Bus
3.1 General Information
CAN stands for Controller Area Network protocol. CAN Bus features:
• Fieldbus
• Low costs
• High noise immunity
• Bus structure
• Open system
• Fast data transfer for small data packages (up to 8 bytes)
• Error detection by means of CRC (Cyclic Redundancy Check) and frame testing -
Hamming distance 6
• Predictable transmission time for high priority messages (real time behavior)
• Easy use
B&R and CAN
The controller used by B&R (Intel 82527) meets CAN Bus specification 2.0B. Protocols Standard
CAN and Extended CAN can be used on a bus.
B&R software currently supports the standard CAN identifier (29 bit).
3.2 Bus Length
The type of cable used depends on the required bus length and the number of nodes. Bus length
is mainly determined by the bit rate.
The following table includes values for the maximum bus length, depending on the transfer
speed and the Synchronization Jump Width (SJW). Permitted oscillator tolerances are given in
the fourth column.
Figure 219: Lithium Battery