firewire in automation - Hochschule Furtwangenspale/forall/PES/Vorlesung/ppt/... · Dr. Ing. Ji...

Dr. Ing. Jiří Špale, 1394b in automation 1

1394b FireWire

in automation

Dr. Ing. Jiří ŠpaleFurtwangen University, Germany


FireWire = i.Link = IEEE1394

1. History and development2. Main technical features of FireWire3. FireWire versus Ethernet4. Has FireWire its place in automation?

- advantages and disadvantages5. Solutions with FireWire - examples

... Fast serial bus

Abstract:


History and development USA

• 1985 Apple: concept submitted - 2 development goals:- very fast, cheep desktop-LAN, simple in using- successor of SCSIcontemplated area of use: PC internal/external, multimedia

• 1986 development team extended by Sony and other companies IEEE P1394 Working Group build

• 1993 first presentation at Comdex 1993• 1994 1394 Trade Association grounded• 1995 open standard 1394-1995 (S100, S200) accepted by IEEE


• 2000 IEEE 1394a – speed version S400

• 2000 arrival of cheaper concurrence-bus USB 2.0 with 480 Mbit/s⇒ ambition of PC-market-leadership left⇒ new goals: - dominance in multimedia technology

- bus clone for TCP/IP- penetration into industrial automation

• 2002 1394b with speed standards S800, S1600 a S3200new cables, new plugs

• 2003 connection length 72m →→→→ 100m thanks 8B10B-coding• 2004 Wireless FireWire

History and development USA


History and development Europe• 2002 initiative of Nyquist a Wago: 1394 Automation Group created• 2002 presentation of specification 1394AP at SPS/IPC/DRIVES• 2004 fusion of 1394 Automation and 1394 Trade Association

Members of 1394 Automation Group:

Fraunhofer IPMS Dresden (Photonische Mikrosysteme)

Fraunhofer IPT Aachen (Produktionstechnologie)

Institut für Mikroelektronik- und Mechatronik-Systeme

Institute Industrial Technology TNO, Eindhoven

R&D institutions

BaslerVision

Eurotherm, Lust, maxon motor, Moteurs Leroy Somer, StöberBosch Rexroth (Nyquist), DanaherWAGO

Motion

(drives,

control technology,

contact technology)


IEEE1394a / 1394b Features #1• Transmission speed 100, 200, 400 (S100, ...) / 800, 1600, 3200 (S800, ...) Mbit/s

is given by the slowest device – mix of slow and fast devices possible

• Isochronous modus: real-time applications

• Asynchronous modus: peer-to-peer transmission

• Automatic self-identification

• Automatic self-addressing of devices

• Hot-plug: devices can be plugged in the working condition

• 4-wires-cable, event. 2 additive power-leads / 9-wires-cable

• Cable material: STP only / UTP, POF, HCPF, MMF also possible

• Distance between adjacent devices depends of the bus-speed, e.g. 4,5m@S400&STP, 14m@S200&STP / 100m@S100&UTP

• No bus-terminators necessary

• Bidirectional transmission in packets


IEEE1394a / 1394b Features #2• Topology: trees only, ring structures not possible / ring structures allowed

• Max. daisy chain length: 72m

• Max. 63 devices connectable at 1 bus(max. 16 devices at 1 daisy chain)

• Multi-master: 1 – 63 masters possible

• Max. 1023 busses connectable via bridges

• TCP/IP: IP transmission over 1394 possible (standard@Mac); features comparable with GB-eth

• On-bus power: 8..33V; 1,5A; max. 48W

• drivers: Standard@Windows>98SE,Mac>8.6,Linux

• 8B10B coding implemented in physical layer

• New signal levels „beta mode“

• New arbitration (protocol BOSS = Bus Ownership / Supervisor / Selector)

• Back-compatible with 1394a


Backplane environment

• Uses two single-ended conductors

• Can be used on the two serial bus pins defined in several common backplane busses (i.e. VME)


Cable environment #1

• IEEE 1394a: Thin flexible 6-wire cable:two differential signal pairs and a power pair- a group of consumer A/V companies has proposed an alternate cable without the power pair=> 4-wire cable- smaller connector- already has been used in some products on the market- connected in a non-cyclic tree

• IEEE 1394b: 9-wire cable- new connectors


Cable environment #2

• Each node regenerates signals

• Maximum length between adjacent nodes- 4.5 m by standard cable- 10 m by well shielded cables- 70 m by use of repeaters

• No more that 16 hops between any two nodes

• Well suited for connecting multiple units- Inside the same enclosure (such as CPU board to disk drive)- In separate enclosures (such as camcorder to VCR)


What kind of protocols does 1394

define?

• PHY- Bits on the wire- Arbitration- Reset & bus configuration

• Link- Packets on the wire

• Transaction- Read, write, lock, etc.

• Bus management


Higher layer protocols

• SBP- serial bus transport for SCSI-3- in addition to standard data read/write, SBP specifies isochronous storage and playback

• A/V command set- connection management- device control- data packet format


IEEE 1394 protocol stack

• ISO-7

7 Application layer6 Presentation layer5 Session layer4 Transport layer3 Network layer2 Data link layer1 Physical layer

• IEEE 1394

7-5 Bus manager

4-3 Transaction layer (Resource manager)2 Link layer1 Physical layer


Protocol StackApplication Layer

Hardware

Serial Bus Management

Firmware

Physical Layer

Link Layer

Encode/Decode Arbitration Media Interface

CycleControl Packet Transmitter Packet Receiver

FirmwareTransaction Layer

Cycle Master

Elektrical signals and mechanical interface

Symbols

Cable

Packets

Isochronous

transmission

Asynchr. transmission (read, write, lock)Configuration

Error check

IsochronousResource

Manager (IRM)

Node Control

Bus Manager


Main functions of PHY

• To translate the symbols used by the Link Layer Control (LLC) into the appropriate signals and vice versa

• to define the mechanical and electrical connections for the bus

• to provide arbitration to ensure that only one node or device can transmit data at a given time

• to ensure that all devices have an equitable access to the bus


Main functions of LINK

• To manage the data packet assembly/disassembly for both the asynchronous and the isochronous data

• To handle addressing, error control, data framing

• To generate the packet cycle timing and synchronizing signals


Transaction layer

• Control of the asynchronous data streamwrite operation : transmitter → receiver read operation: transmitter ← receiverlock operation: data is send on a round trip through the processing at both ends of the chain (test & control function)


Bus management layer

• Controls function of- PHY- LINK- transaction layerand operate in both the HW and SW

• There are 3 possible modes- fully managed system- non-managed system- limited bus management system


Fully managed system

• Host present: PC, smart device

• All modes of data transfer for up to 64 channels supported

• power management

• bus optimization

• able to create - rate maps- bus topology diagrams


Non-managed bus

• Cycle master present

• asynchronous data transfer only

• Examples:transfer camera - hard disk

hard disk - printer


Limited bus management

• Power management ability limited

• handling of both the asynchronous and isochronous data transfer for 8 - 64 channels possible


Bus managementWhat FireWire does not know:• No Host needed (necessary at USB)

Control functions can be executed by any device with appropriate technical sources

• User setupNo address configuration by a user is needed, no configuration programs must be launched

The following control functions are possible:• System Root-node

device with the highest node address - asynchronous arbitration (= decision which node should manage the bus)- synchronization of all devices for the isochr. transmission (cycle master role)

• Isochronous Resource Manager, IRM. - channel management, bandwidth allocation to discrete channels

• Bus Manager- bandwidth optimization

• Power Manager- power economization


Identification phases and arbitration• reset

- Occurs always if the bus must be reconfigured- always if a new device is plugged/unplugged and if the cycle master changes

• tree identification• the parent-child relation is recognized

• self-identification• physical IDs are assigned to the nodes• the neighbors are informed about the own speed capacity

• normally arbitration• decision what node should manage the bus• root-node hat normally the highest priority


Bus reset• occurs when any node is connected or disconnected

• takes ca. 300 µs

• the following activities run:- assignment of node addresses (node ID)- root node is choosen- assignment of other functions- eventually: other bus topology is done

Configuration ROM ... device information


Identification phases and arbitration• reset

- Occurs always if the bus must be reconfigured- always if a new device is plugged/unplugged and if the cycle master changes

• tree identification• the parent-child relation is recognized

• self-identification• physical IDs are assigned to the nodes• the neighbors are informed about the own speed capacity

• normally arbitration• decision what node should manage the bus• root-node hat normally the highest priority


Tree identification #1

branch

branch

branch

p

leaf leaf

After reset, the nodes onlyKnow if they arebranch (>1 port connected) o. leaf (exactly 1 port connected)


Tree identification #2

ch bus manager ch

p

After tree identification,the root node is choosen (event. other functions too) and every connected portis signed as chíld or parent

ch root ch

leaf

p

leaf

p

leaf

p


Self-identification #1

ch bus manager ch

p

ID 3

After self-identification,each node has its own explicit physical IDand the topology wasidentified by broadcasting

ch root ch

ID 4

leaf

p

ID 0

leaf

p

ID 1

leaf

p

ID 2


Self-identification #2

control / IPCch bus manager ch

p

ID 3

Configuration ROM wasread and the special node features was provided

drivech root ch

ID 4

IO module

leaf

p

ID 0

cameraleaf

p

ID 1

driveleaf

p

ID 2


Normally arbitration #1


p

ID 3

Example:Nodes #0 and #2 requirethe bus in the samemoment. They send therequest to their parents...

drivech root ch

ID 4

IO modul

leaf

p

ID 0

cameraleaf

p

ID 1

driveleaf

p

ID 2

request

request




p

ID 3

Example:They pass the requestto their parents

drivech root ch

ID 4

IO module

leaf

p

ID 0

cameraleaf

p

ID 1

driveleaf

p

ID 2

request

request

request




p

ID 3

Example:The asked parents deny access to theirother children

drivech root ch

ID 4

IO module

leaf

p

ID 0

cameraleaf

p

ID 1

driveleaf

p

ID 2

request

request

request

deny

deny




p

ID 3

Root grants the access tothe node which request it had received at first (#0). The node #3 had loose,that’s why it cancels itsrequest and sends theprohibition to the node #2

drivech root ch

ID 4

IO module

leaf

p

ID 0

cameraleaf

p

ID 1

driveleaf

p

ID 2

request

request

deny

deny

grant

deny



control/ IPCch bus manager ch

p

ID 3

Example:The winning node #0 begins with datatransmission and theloosing node #2 cancels its request

drivech root ch

ID 4

IO module

leaf

p

ID 0

cameraleaf

p

ID 1

driveleaf

p

ID 2

data prefix deny

deny

grant

deny




p

ID 3

Node #4 sees the data prefix,it cancels its grant; deny changes in a data channel – all data flow into the right direction

drivech root ch

ID 4

IO module

leaf

p

ID 0

cameraleaf

p

ID 1

driveleaf

p

ID 2

data prefix data prefix

data prefix

data prefix


Address space

initial memory space

256TB-512MB=268 434 944MB

bus 0(nodes 0..63)

bus 1(nodes 0..63)

bus 1023local bus (nodes 0..63)

…

node 0

node 1

node 2

node 62

node 63(broadcast)

…

register space 256MB

(memoryaddressing)

private space256MB

256TB/node

control&statusregisters (CSR)

serial bus

ROM1kB

initial node space

Example of an address:

initial units space

256MB/register 2kB „boot“

63 54 53 48 47 0

0x3FE

bus 1022(nodes 0..63)

0x3E 0xFFFFF000020010 bits 6 bits 48 bits


Isochronous and asynchronous modes

• Cycle sync is always send by cycle master; cycle master must be root node

• Asynchronous and isochronous transactions split the bus bandwidth• Isochronous transactions can use max. 80% of the cycle length, i.e. 100µs• Asynchronous transactions can use 125µs minus isochronous transactions time

• Isochr. transactions are optional only; only async. traffic on the bus is also possible

Nominal cycle length = 125µs

Isochronous transaction Asynchronous transaction

cycle

sync

cycle

sync

Isochronous (short)

subaction gaps

Asynchronous (long)

subaction gaps (~10µs)

Cycle Start Telegram (CTS)

Acknowledge

gaps (~50ns)

AC

K

AC

K


Isochronous transactionCycle n (125µs)

Isochronous transaction Asyn. transaction

CTS

CH61

CH57 3

CH11

CH61

CH57 3

CH11

Cycle n+1

• Bandwidth reservation for isochronous transactions given by IRM• „isochronous talker“ designates the packets by channel numbers 0-63• Each node can listen if needed ( „listener“ ),

i.e. only one node sends, multiple nodes can receive• Isochronous packets are not acknowledged• Within each cycle the channels are send in the same sequence till transmission end


Asynchronous transaction #1

• Bus Config: all nodes take part• Arbitration: all nodes take part which want access the bus; only the winner may send• ACK: during the request subaction, ACK is send by relevant node a contrariwise• *: The communication partner does not rise to answer: this time may be used by

other packets

- is a transaction between 2 nodesCycle n (125µs)

Asyn. transaction

CTS

Cycle n+1

AC

K

AC

K

AR

B

AR

B

Pak

et

A

Pak

et

B

AC

K

AR

B

Pak

et

C

Bus Config

Asyn. transaction

Request

subaction

Request

subaction

Request

subactionResponse

subaction

ArbitrationGaps (bus is free)

*The isochronoustransaction isabsent in this cycle


Asynchronous transaction #2Cycle n (125µs)

CTS

Asyn. transaction

Cycle n+1 (125µs)

CTS

Asynchronous packets can delay the CST

• CST contents the 32-bit-information about the beginning of the sending with the accuracy of 40 ns

• Synchronization of the clock signal takes place in the link layer IC of the receiving node

• Accuracy of 125 µs-clock: < 500ps (jitter)


FireWire vs. ethernetRequirements for modern distributed automation systems:(1) compatible IT-systems, data transfer from fieldbus-environment into the control

administrative(2) integrity of automation system(3) low cost(4) visual information transmission (graphical monitoring, vision)(5) Real-time motion control data transmission (motion control)(6) interoperability between components of different manufacturer

Solution:1,3,6 → ethernet4,5,(6) → ethernet, its industrial derivates, Profibus, CANbus, SerCos

Problem with (2)1,2,3?,4,5 → FireWire: integrity is an inherent feature due to isochronous mode

FireWire & (6) … solution = 1394 AP


widely spread standardization and acceptance

real-time transmission problems, synchronization problems

Ethernet+

-

Solution:

• network segmentation, data flow restriction (EtherCat), special switches, time slicing systems (Profibus DPV3) → limitation of ethernet universality

• special protocols (Powerlink) → elimination of ethernet universality

• procedure according to IEEE 1588: synchronization of slave-clock with themaster-clock through the use of telegrams; compenzation of the unknown data transmission time throught the networkthrough the use of feedback-loops for time measurement in both master andslave nodes- software solution → big jitter (~1µs),jitter grows onward with the load on the bus

- solution by special hardware + protocol filtering → expensive


FireWire• jitter < 500 ps

• asynchronous and isochronous modes

• self-identification and automatic parametrization of nodes in theworking condition

• hardware implementation of protocols

• co-existance of protocols for

- machine control- programmable logic controller- video applications- internet protocols

on common physical interface


PHY circuits connection example

TPA:

• sends Strobe

• receives Data

TPB:

• sends Data

• receives Strobe

Bidirectional signals TPA, TPB:

Both signals are used for thearbitration as well


Data and Strobe coding

Data

Strobe

CLK(delayed)

1 0 0 0 0 0 01 1 1

CLK = Data ⊕ StrobeData change due to Strobe instead of CLK

Level change at Data and at Strobe never in the same timeResult: jitter < 500ps


1394AP

common base for automation components motion, vision a I/O

Following functionalities are defined in application layer:

• Format of transmitted data• Network management• Data Synchronization• Special register sets for node external control


IEEE1394AP for industrial automationCommunication Profiles and Device Profiles

IEEE1394AP (Application Layer for Industrial Automation)

Bus Management Interface AsynchronousTransfer Interface Isochronous Transfer Interface

Hardware

Management Layer

Firmware

Physical Layer

Link Layer

FirmwareTransaction Layer

Cycle Master

Electrical signals and mechanical interface

Symbols

Cable

Packets

Link

Layer

Services

Transaction Layer ServicesManagement Layer Services

Isochronous Resource Manager

Node Control

Bus Manager

např. 1394CP (1394 Communication Profile for CANopen

Management Services Servis Data Services Servis Data Services


1394AP: key wordsApplication Master (AM)• network control• cyclic data transmission to slave nodes (slave = all other nodes)• AM is mostly IP

Master Data Telegram (MDT)• source = AM, target(s) = slave node(s)• content process data• transmitted in every data packet• slave nodes filtrates the relevant data

Application Cycle (AC)

• gives the transmission speed of MDT• different at each application• fast or very accurate systems: AC = 1394 cycle

• lower performance systems: AC disposed in multiple 1394 cycles

Device Data Telegram (DDT)

• both source and target = slave nodes• data packet content:

e.g. state and control informations


1394AP: communication profiles

MDT, DDT ... Containers for control and state variables

Communication profiles:• Interpretation of MDT, DDT data• Functional overlay of 1394AP

Example:1394CP for CANopen• Application software written for CAN functions also in 1394CP/CAN

based devices


FireWire in the industry: advantages• Acquisition of video information (> 800Mbit/s)

Video information ca be transmitted together with inputs and outputs and with the motor control data

• high control accuracy, jitter < 500 ps• asynchronous transmission

for critical data or security-sensible data - information if transmission succeeded or about the reason of bad success

• Flexibility of 1394b network topology

both trees and ringsAll nodes are of the same value ⇒ no real-time demands on the central control, normally PC quite sufficient.

• integration of typical ethernet based services possible (IPower 1394)

nevertheless rather mixed configurations are expected in the praxis: - 1394 for real-time components - ethernet for control, service and visualization


FireWire in the industry: disadvantages

• insufficient throughput in office networks

• advantages of FireWire concern only a strait utilization area

• only the 1394b standard is suitable for the industry

due to cable length, there are only a limited variety of 1394b IC on the market

• limited number of nodes, limited throughput

at cable length 100m and speed 100Mbit/s

• in systems with only little number of real-time components

Ethernet Powerlink is preferable

• persistence of users


(isochronous)

FireWire in the industry: example 1

Source:J. Gorka, 1394 Automation e.V. , 32423 Minden



Source:J. Gorka, 1394 Automation e.V. , 32423 Minden

Ethernet TCP/IP

Ethernet TCP/IP

VisualizationVisualization

Gateway

Client in office networks environment

ConfigurationService

Application

Windows XP

FireWireReal-timeenvironment



Source: Fraunhofer IPT Aachen

Accurate turning lathe with high dynamics for treatment of

Non-circular intersection faces

• controller Nyquist/Kollmorgen• aim: optimal speed / accuracy• set-values transmitted as splines with variable

spline time to servo-amplifiers• the speed is planed in an IPC, original splines are

saved • interpolation of the spline on the speed requested

(4000 points/sec) is performed only in axes-drives• tested workpiece:

sinusoidal Al-screwline with passing from 4 to 2liftings per revolution

• lathe work speed: 400 rev/min



Zdroj: Rexroth, Bosch Group

• Controller and drive unit in one• aim: application 100-1000 W• 1394 b• through 4 drives cards• 2 axes: 500W per axis or 1 axis 1 kW• 800 Mbit/s, real-time• more-channel SW oscilloscope on a PC

Bosch Rexroth NYCe 4000



SD Serie 460SD Serie 230

2.400 through 24.000 W600 through 15.000 WOutput power

230 VAC or 460 VAC115 VAC or 230 VACInput voltage

Zdroj: ORMEC

ORMEC ServoWire SD drives

SMLC-160SMLC-80SMLC-30SMLC-SA

2 PC 104 +1 additional slot



18 built-in I/O18 built-in I/O18 built-in I/O29 built-in I/O

1,4 GHz Pentium M933 MHz Pentium III650 MHz Celeron400 MHz Celeron

through 16 axesthrough 8 axesthrough 3 axes1-axis-systems with integrated amplifier

ORMEC controller SMLC


Who uses industrial FireWire

1394 automation group members (excluding research)

Others


References 1. GORKA, J.: FireWire als Feldbus? Wie 1394AP die industrielle Highend-

Kommunikation IT-kompatibel macht, SPS-Magazin, 2003

2. GORKA, J.: 1394automation e.V. Ergebnisse und nächsten Schritte, SPS-

Magazin, 2004

3. PRESHER, A.: 1394b Motion Networking. In: Design News, Nr.6, Vol. 2006

4. RUIZ, L., DALLEMAGNE, Ph., DECONTIGNIE, J.D.: Using Firewire as

Industrial Network, report CSEM, Real-Time and Networking Group, Neuchâtel, 1999

5. SCHOLLES, M. : New FireWire standard targets industrial applications, VisionSystem Design, November 2005

6. TESCHLER, L.: Ready, aim, FireWire. In: Machine Design, Nr. 6, Vol. 2005

7. VAESSEN, D.: FireWire in Automatisierungseinsatz – es geht voran, IEE Nr.

11, Vol. 2004


Web Sources1. www.1394.org

2. www.fcga.de

3. www.ipms.fraunhofer.de

4. www.zayante.com

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