Can bus bandwidth limit, 62 appendices, Other devices – MoTeC ADL3 EDL3 User Manual

Page 66

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62 Appendices

CAN Bus Bandwidth Limit

The total available CAN bandwidth available on a single CAN bus is
1 Mbit/sec.

The bandwidth used by the total of all devices on a particular CAN bus must
not exceed approximately 90% of this value (900000 bits/second)

If the total bandwidth required exceeds this specification then some devices
should be connected to the second CAN bus.

Note: ADL3 Dash Manager will warn if the bandwidth is likely to be exceeded.

VIM

Approximate Bandwidth = Total Measurement Rate (samples/sec) x 30 (bits
per sample)

Note: The Measurement Rate for each input is equal to the logging rate for
that input or 50 Hz, whichever is higher.

Example Calculation

4 channels at 2000 Hz

20 channels at 500 Hz

40 channels at 20 Hz (Occupies 50 Hz)

Calculation:

Total Measurement Rate = 4 x 2000 + 20 x 500 + 40 x 50 =
20000 (samples/sec)

Approximate Bandwidth = 20000 x 30 = 600000 (bits/sec)

E888/E816

Device on first CAN Address

Bandwidth = 145000 (bits/sec)

Device on second CAN Address

Bandwidth = 55000 (bits/sec)

Other Devices

BR2, SLM , PLM

Negligible

SDL, ADL2, MDD, M800 ECU TBD

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