real-time ethernet protocol for connection of distributed...

1GDNET , Riccardo Ragnoli WFCS 2006

Torino, 27 June 2006 WFCS INDUSTRY DAY

Riccardo RagnoliSoftware Research Dept.

[email protected]

Real-time Ethernet Protocol

for connection of

distributed I/O


COMPONENTS

Indication and control

of process variables

SENSORSMeasurement of

process variables

SYSTEMSHardware & Software for Automation

and Control of machines and industrial processes

MOTION CONTROL CC and AC motors

control

Gefran in the world


Plastic machinery

•EXTRUSION

•BLOW MOULDING

•INJECTION MOULDING

•THERMOFORMING


Plastic machinery: critical aspects

Number

of I/O

Timing performance

Numberof

Nodes

Jitter free

1 - 23 - 43 - 42 - 3

EXTRUSION BLOW MOULDING INJECTION MOULDINGTHERMOFORMING

= low critical = medium critical = high critical


Plastic machinery: injection

• Main regulation

Cylinder temperature: typ . 8 thermocouples

Hot runner temperature: typ. 8 thermocouples

Position, Speed and Pressure of injection movements: analog input and output

Position Speed and Pressure of mould movements: analog input and output

• Type and number of I/O (typ.) = 48 DI, 48 DO, 8 AI, 8 AO, 16 Thermo Loop


Threshold interception during injection movement Threshold interception during injection movement Plastic machinery: injection

PressureSpeed Injectionposition

Out flow

Threshold

Out pressure

t

Analoginput/output

Td : must be known and repeteable(Td ~ 1 ms, σTd ~ 3 µs)

Td

Position




Position

transducer

Td

Out flowOut pressure

Master


Patent Pending

First RTE protocol in Italy

First plant running from 2004

Developed in collaboration with

University of Brescia

GDNET the solution of Gefran

State of the art (2003)

Fast I/O: local busDistributed I/O: CANopen

2003: no open RTE available

Technical requirements

I/O distribute High performance

Typ.Tc <= 1ms Jitter < 10µs

Few nodes (typ. 4)

Master requirements

PC-based R.T.O.S

No microprocessor for communicationVery light Software for

communication.

Industrial requirements

Std. Ethernet Hardware - RJ45, cat5, 100BaseT

- Different network cards- switch or hub


GDNET: nodesGF-BOX: Network Master

• CPU Intel® Celeron® 400MHz, R.T.O.S • Etx technology (ethernet chip on board)• SoftPlc and HMI • GDNet interrupt handled every Tc ± 20 µs

• µP 32 bit, 200 MHz , 100Base-T, RJ45• Local timing (resolution ~150ns)• A/D: 16 bit (Tconv ~ 6µs)• D/A: 16 bit (Tconv ~ 10µs)• Thermal module = 8 thermocouples/RTD• ….

80Mbps

GILOGIK II: Slave R-ETH100


• Each node Si: 1536 point of I/O ( 48 word Input / 48 word Output), 128 Thermo input

• Acyclic data A: up to 255 blocks of 64 word (16320 word)

• Network Tc min is a function of switch delay (configuration) and number of nodes (e.g. “store&forward” switch, 4 nodes, Tc=200 µs)

GDNET cycle

Logical Network1 Logical Network2 Logical Network3

S1

M A

S1 S2 SN NA

•M: cyclic output data A: acyclic data S: cyclic input data N: null slot

Up to 3 Logical networks

Cycle Tc Cycle Tc Cycle Tc

Up to 21 nodes


GDNET Messages

HEADER

NetIDNcycle

MSGtype

Alias DataAlias Info

Alias Type

Alias DataWord 1-64

4 byte 2 byte 128 byte

Alias Message A

Master Message M

HEADER SLAVE 1 SLAVE N

NetID, Ncycle Msgtype , …

Aliasinfo

Event ack

Direct Acc.

DBout1 (word 1-48)

6 byte 114 byte 114 byte

Sincro DBout

Event ack

Direct Acc.

DBoutn(word 1-48)

Sincro DBout

4 byte 114 byte

Slave Message S

HEADER SLAVE N

NetIDNcycle

Alias info

Event

Direct Acc.

DBinput(word 1-48)

Sincro DBin

Each message takes a known time:

- M: < 66.4 µs - S: 11.52 µs -A: 12.8 µs

Tc is simple to design with constant bandwitdh occupancy

Direct Access:

writing or reading one word into I/O space or acyclic data

Event:

slave is programmable between always replay to Master message

or event depending

Sincro

- SincroDBin: timing input (e.g. Threshold)

- SincroDbout: programmable timing output


GDNET performance

Minimum cycle time (NS < 8)

Tc = Tq ((NSW + 1) (NS + NA + NN ) + NS ))

Minimum cycle time (NS >= 8) Nln = number of logical network

Tc = Tq* Nln ((NSW + 1) (NS + NA + NN ) + NS ))

Maximum Band = (NS + NA ) / Tc

NS = number of nodes NA = number of slot for acyclic data NN number of null slot NSW = number of Switch

Maximum band

0,00%

12,00%

24,00%

36,00%

48,00%

60,00%

1 3 5 7 9 11 13 15 17 19 21

Number of nodes

Nsw=1Nsw=2Nsw=3Nsw=4Nsw=5

Cycle time

0,00

500,00

1000,00

1500,00

2000,00

2500,001 3 5 7 9 11 13 15 17 19 21

Number of nodes

Tc [u

s]

Nsw=1Nsw=2Nsw=3Nsw=4Nsw=5


GDNET nodes synchronization

M M M

Syncout is programmable

Syncin synchronized to the average time distance between M messages (Delta RxM)

Tck = Tck-1 + α (TrxMk – TrxMk-1)

Synck = Synck-1 + Tck + β (TrxMk-1- Synck-1)

Tc

Syncin Syncout Syncin Syncin SyncinSyncout Syncout

TcTc

Delta RxM




Out flow

Threshold

Out pressure

t

Analoginput/output

Td : must be known and repeteable(Td ~ 1 ms, σTd ~ 3 µs)

Td

Position




Position

transducer

Td

Out flowOut pressure

Master


MM M

t

New_Value

a

IN

Threshold

Syncin1

Crossin

Old_Value

b’

bc’

c

Crossin = (Syncin2-Syncin1)Threshold-Old_Value

New_Value- Old_ValueSyncin1 +

Crossin

SS S S SSyncout =

Crossin

Jitter 0

Analog input

Analog output

M M

1

1. Instant of threshold interception

2. Slave sends message to master

3. Master acquires information

4. Master sends message with action for ouput

5. Output action is performed

Syncin Syncout

TcSyncin Syncin Syncin Syncin SyncinSyncout Syncout Syncout Syncout

Syncin2 Syncin3

GDNET nodes synchronization

2

3 4

5


GDNET: test measure

Outdig1

Indig1

Outdig2

Outdig3

Outdig6

Outdig5

Outdig4

Syncin

Analog input

OutdigA

OutdigA

Node 1

Node 2

Node 3

Node 4

Node 5

Node 6

Syncin

OutdigA

Syncin


GDNET: measurement results

0%

1%

2%

3%

4%

5%

6%

7%

8%

375,991 375,995 375,999 376,003 376,007 376,011

Time (us)

Freq

uenc

y

0%1%2%3%4%5%6%7%8%9%

362,4 367,5 372,5 377,5 382,5 387,6

Time (us)

Freq

uenc

y

Tc = 375 µs Ns = 6 (imposed)

Node 1

Average value = 376.003 µs

Min Value = 363,443 µs

Max Value = 388,573 µs

σTrxM = 3.7 µs

Measure of Syncink –Syncink-1

(time distance between two Syncin signals)

Average value = 376.001 µs

σSincin << 100 ns

Measure of TrxMk – TrxMk-1

(time distance between two M message)

Tc = 375 µs Ns = 6 (imposed)

Node 5

25 µs


GDNET: measurement resultsMeasure of Syncin1 – Syncin2


Average value = 1,27 µs

σ Syncin1 – Syncin2 = 0,14 µs

Average value = 1,83 µs

σ Syncin1 – Syncin6 = 0,23 µs

Node 1 – 2 (under the same switch) Node 1 – 6 (under different switch)

0%

2%

4%

6%

8%

10%

12%

0,584 0,808 1,032 1,256 1,480 1,704

Time (us)

Freq

uenc

y

0%

2%

4%

6%

8%

10%

12%

1,068 1,373 1,679 1,984 2,290 2,595

Time (us)

Freq

uenc

y

Tc = 375 µs Ns = 6 (imposed) Tc = 375 µs Ns = 6 (imposed)

Measure of Syncin1 – Syncin6




Average value of TL= 1503,9 µs

σ TL = 0, 25 µs

TL= 4 * Tc = 1500 µs

0%

5%

10%

15%

20%

25%

1503,2 1504,0 1504,8

Time (us)

Freq

uenc

y

0%

2%

4%

6%

8%

10%

12%

14%

1,1 1,5 2,0 2,4 2,8

Time (us)Fr

eque

ncy

Average value of ∆TL= 2,04 µs

σ ∆TL = 0, 22 µs

Outdig1 =

not (Indig1)

Outdig1 =

not (Indig1)

Outdig6 =

not (Indig1)

TL

Tc = 375 µs , Ns = 6 (imposed)

Node 1

∆TL

Tc = 375 µs , Ns = 6 (imposed)

Node 1 - 6


GDNET: test measure

Outdig1

Indig1

Outdig2

Outdig3

Outdig6

Outdig5

Outdig4

Syincin

Analog input

OutdigA

OutdigA

Node 1

Node 2

Node 3

Node 4

Node 5

Node 6

Syncin

OutdigA

Syncin


Threshold interception: Node 1Threshold interception: Node 1

OutdigA

Trigger Trigger Trigger

Delay in threshold interceptionDelay in threshold interception Delay in threshold interceptionDelay in threshold interception

0%

1%

2%

3%

4%

5%

6%

7%

8%

9303,4 9305,9 9308,3 9310,8 9313,3

Time (us)

Freq

uenc

y

Ns = 6, Tc = 375

Average ThreShInt = 9,309 ms

Delay = ThreShInt – Tr

Delay = (9,309 – 7,8) ms = 1509 µs

Delay ~ 4 * Tc

σ threshint = 1,84 µs

Tr Tr

ThreshInt ThreshInt


Threshold

Analog Input


Threshold interception: Node 2 (the same switch of Node 1)Threshold interception: Node 2 (the same switch of Node 1)



Tr Tr

ThreshInt ThreshInt

0%1%2%3%4%5%6%7%8%9%

10%

9304,1 9307,4 9310,6 9313,9 9317,2

Time (us)

Freq

uenc

y

Ns = 6, Tc = 375



Delay = (9,310 – 7,8) ms = 1510 µs

Delay ~ 4 * Tc



Analog Input

Threshold

OutdigA


Threshold interception: Node 6 (not the same switch of Node 1)Threshold interception: Node 6 (not the same switch of Node 1)



Tr Tr

ThreshInt ThreshInt

0%1%2%3%4%5%6%7%8%9%

10%

9304,5 9307,4 9310,3 9313,1 9316,0

Time (us)

Freq

uenc

y

Ns = 6, Tc = 375



Delay = (9,311 – 7,8) ms = 1511 µs

Delay ~ 4 * Tc



Analog Input

Threshold

OutdigA


Plastic machinery: gdnet applications

Numberof

Nodes

Number of

installations

3000200800600

100050200150

EXTRUSION BLOW MOULDING INJECTION MOULDINGTHERMOFORMING

Since2005 until today

• Test measurement results are very satisfying and design compliant

• Machine applications confirm test measure results

real-time ethernet protocol for connection of distributed...

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