CAN

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CAN F(lexible) D(ata-rate)

Holger Zeltwanger

CAN

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First press release

Intel’s 82526 CAN stand-alone controller chip supported data-rates up to 1 Mbit/s

CAN

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History of CAN

u  1991: Bosch CAN 2.0 A/B specificationu  1993: ISO 11898 — CAN protocol and high-speed transceiveru  2003: ISO 11898-1 — CAN data link layeru  2003: ISO 11898-2 — High-speed physical layeru  2004: ISO 16845 — CAN conformance test planu  2004: ISO 11898-4 — Time-triggered CAN (TTCAN)u  2007: ISO 11898-5 — High-speed low-power physical layeru  2013: ISO 11898-6 — High-speed selective wake-up physical layeru  2014: ISO 16845-2 — ISO 11898-6 conformance test planu  2015: ISO 11898-1 — Classical CAN and CAN FD data link layeru  2016: ISO 11898-2 — Improved high-speed physical layer u  2016: ISO 16845-1 — ISO 11898-1:2015 conformance test planu  2017: ISO 16845-2 — ISO 11898-2:2016 conformance test plan

SAE conference

1986

Bosch CAN 2.0 A/B 1991

ISO 11898 CAN 1993

re-organized ISO 11898-1/2

2003

ISO 11898-1 with CAN FD

2015

CAN

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CAN FD protocol

Arbitration phase Data transmission phase Arbitration phase

50 kbit/s to 1 Mbit/s 50 kbit/s to more than 1 Mbit/s* 50 kbit/s to 1 Mbit/s

Up to 64-byte payload

* Currently the ISO 11898-2:2016 standard specifies the parameters for transceivers supporting bit-rates up to 2 Mbit/s and up to 5 Mbit/s.S

ourc

e: B

osch

CAN

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High-speed transmission ISO 11898-2:2003Physical media attachment (PMA)u Up to 1 Mbit/s

ISO 11898-5:2007Low-power modeu Remote wake-up

ISO 11898-6:2013Partial networkingu Selective wake-up

ISO 11898-2:2016Physical media attachment (PMA) with optional low-power mode and partial networkingu Up to 5 Mbit/su Remote wake-upu Selective wake-up

CAN

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Conformance test plans International standardsu  ISO 16845-1 (2nd edition): Classical CAN and CAN FDu  ISO 16845-2 (2nd edition): High-speed transceiver (optionally

with low-power mode and selected wake-up functionality)

NOTE Conformance testing is like spellchecking in human communication. It increases theprobability of interoperability, but doesn’t guarantee it! CAN controllers and CAN transceiverstested by different test plan implementations can have different results. Complementary interoperability tests (e.g. plug-fests) are necessary to satisfysystem designers.

CAN

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Network system testing

u Option 1: CAN FD plugfestsTemporarily network at different locations in the world.

u Option 2: “Golden” CAN FD system testing For example permanently installed in CiA office; manufacturers can test their products in this network.

CAN

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CAN FD plug-fest

CiA organizes worldwide CAN FD plug-fests to proof the interoperability of CAN FD products from different manufacturers as well as the system design recommendations.

Due to the higher bit-rates in the data-phase the physical layer design

needs to be more serious. For example, all nodes

should use the same oscillator frequency and

the very same time-quanta length in arbitration and

data phase (CiA recommendation.

CAN

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CAN FD plugfest 2016

ECU1

ECU2

ECU3

ECU4

ECU5

ECU6

ECU7

ECU8

ECU9

GW-ECU

Seg1 Seg2 Seg3

(Each Segment varies in length 0.5m to 3.0m)

(Each Stub varies in length 0.1m to 0.75m)

Entire harness length <20m

Twisted Pair CAN wiring in harness

CAN-FD PlugFest - Simplified CAN wiring diagram

...

Stub

1

Stub

2

Stub

3

ECU14

ECU13

ECU12

ECU10

......

ECU14

ECU11

Inline

Notes: - All ECUx nodes are terminated with a Female DB-9 connector with CANH on PinL and CANL on Pin2- One Inline will be provided; this would be a male-to-female DB-9 to join the branch.- Stubs would be various types of wires that are soldered into the main backbone. - Stub connections will have ~50mm separation between solder connection- No termination resistors are included in the harness. These will be provided at testing time as DB-9 pass-through adaptors.

~50mm

Sour

ce: F

ord

April/June in USA and Germany.

CAN

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Plugfest 2016 in Detroit, MI u  Robustness and reliability tests

(edge shifts at various positions of the data frame, bit flips of reserved bits)

u Oscillator tolerance test(fnom + 2,5 %, fnom -1,5 %)

u Glitches in res-bitu Wiring harness tests

(Ford and GM cabling)u  RSC (ringing suppression circuitry) testing

(RSC is specified in CiA 601-4)

Most of the tests were performed with 500 kbit/s (arbitration) and 2 Mbit/s (dataphase)

CAN

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Plugfest in Nuremberg 2016 Corner-case tests: Two ACK bits

Border-case tests: 1,2-µs shift of res-to-BRS edge

Diff (CAN_L–CAN_H)

Dominant

Recessive

CAN_H

CAN_L

FDF res BRS 1,7 us

ESI, DLC, … 1,2 us shifted edge

CAN

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Plug-fest experiences u  The length of time quantum in arbitration phase

should be not longer than in the data phase (this means the nominal number of time quanta in arbitration phase is increased).

u  The Sample Points should be configured in all nodes exactly at the very same position (this applies to the arbitration and the data-phase).

u  The Sample Point for the data phase should be placed in the middle between the time when the bus signal has stabilized after a possible late edge at the beginning of the bit and a possible early edge at the end of that bit.

CAN

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Node and network design u  ISO 11898-1 and ISO 11898-2 do not specify node (host

controller set-ups) and network design!u  CiA 601 series provides node and network design

recommendations and rules (not just for passenger cars).u  SAE J2284-4/5 recommended practices specify ECU and

network design for dedicated automotive applications.

CAN

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“Workshop” tool to vehicle Tool IVN

gate-way

ISO 11898-2:2016

CAN-H

CAN-LISO 22900-2:2015

•  Oscillator frequency not specified•  Time quantum length not specified•  Cable parameters not specified•  Connector parameters not specified•  Data-phase SJW in percentage of the bit-time (15 %);

this implies the data-phase sample point in percentage of the bit-time

ISO 15765-5:201?

Not yet standardized

RTTµC

CAN (FD)

µCCAN (FD)

T

NOTE The legacy network specification doesn’t support higher data-phase bit-rates. Perhaps transceivers/SBCs with ringing suppression compliant to CiA 601-4 will work (not yet tested and approved).

CAN

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CiA 601 series CAN FD node and system designu  CiA 601-1 (version 2.0): Physical interface

implementation *u  CiA 601-2 (version 1.0): Controller interface

recommendation **u  CiA 601-3: System design recommendation ***u  CiA 601-4 (version 2.0): Ringing suppression

circuitry ***u  CiA 601-5: Reference topology examples ***

* Released as Draft Standard (DS) (free-of-charge for CiA members, non-members need to buy)** Released as Draft Standard Proposal (DSP) (free-of-charge for CiA members, non-members need to buy)*** Still under development (available only for CiA members as Work Draft)

CiA

® 601 Draft Standard Proposal

Node and system design

Part 1: Physical interface implementation

This DSP is for CiA members only and may be changed without notification.

Version: 1.0.0

04 August 2015

CAN in Automation (CiA) e. V.

CAN

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Bit-timing recommendation u  Set tqA = tqD (this reduces the quantization error);

u Make tqA as short as possible (this minimizes the quantization error);

u  Choose the highest available CAN clock frequency (e.g. 80 MHz);

u  All nodes should have the very same sample-point, in both arbitration and data-phase bit different (but these sample-point may be different);

u  SJWA and SJWD should be as large as possible (this makes the network more robust);

u  Enable TDC for data-phase bit-rates for 1 Mbit/s and higher.

CAN

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Additional SAE specifications u  SAE 2284-4: High-speed CAN (HSC) for

vehicle applications at 500 kbit/s with CAN FD data at 2 Mbit/s (bus-line topology)

u  SAE 2284-5: High-speed CAN (HSC) for vehicle applications at 500 kbit/s with CAN FD data at 5 Mbit/s (point-to-point)

Both recommended practices are based on ISO 11898-2:2016. They specify network topology including termination, ECU (electronic control unit) requirements (CAN FD controllers and CAN transceivers), bit-timing settings, fault behavior, EMC (electromagnetic compatibility) requirements, etc. They are guidelines for system designers (carmakers).

CAN

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u  ISO 15765-2:2016 (ISO transport layer)

u  ISO 22900-2:2016 (Diagnostic protocol data unit application programming interface)

u  XCP version 1.2 (ASAM universal measurement and calibration protocol)

u  CiA 602 series (SAE J1939 mapping to CAN FD frames)

u  SAE-IT Arinc 825 CAN FD (application layer)

u  CiA 301 version 5.0 (CANopen FD application layer)

CAN FD support for HLPs

CAN

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CiA 602 series u  CiA 602-1 (Work Draft): CAN FD for commercial vehicles – Part 1:

Physical layeru  CiA 602-2 (Draft Standard Proposal version 1.0): CAN FD for

commercial vehicles – Part 2: Application layer

CAN-ID CAN FD data field (up to 64 byte)

11-bit or 29-bit*

Multi-PDU

C-PDU 1 C-PDU 2 … C-PDU n

“Autosar” PDU short header (4 byte) Payload24-bit ID

PL length

AD(e.g.

J1939PG)

(Safety/security)

trailerTOSa

TL

Data page PDUF PDUS

3 bit

3 bit 2 bit 8 bit 8 bit 8 bit

1 to 60

byte0, 4 or 8

byte

* Includes J1939

Source Address

CAN

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CiA 603: CAN time-stamping This document specifies the time-stamping in CAN and CAN FD networks for Autosar-compliant time management. It is mainly driven by some OEMs’ requirements and is expected to be released as CiA Draft Standard Proposal (similar to Committee Drafts in ISO) in spring 2017.

Florian Hartwich (Bosch) will provide more information in his 16th international CAN Conference paper (Nuremberg, March 7th and 8th).

CAN

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Questions and answers

? !