Netwerken in productiesystemen. Automatiseringspiramide SCADA. Inleiding computersystemen en netwerken deel 2

Inleiding computersystemen en netwerken deel 2

6.1


6.2

Netwerken in productiesystemen

Hogeschool Utrecht / Institute for Information & Communication Technology



6.3


6.4

Automatiseringspiramide

ERP (Enterprise Resource Planning) MES (Manufacturing Execution System) SCADA (Supervisory Control and Data Aquasition)




6.5


6.6

SCADA Supervisory Control and Data Aquasition

• Aannemen en uitvoeren van opdrachten uit een hoger gelegen automatiseringslaag. • Terug melding aan die hogere laag. • Data aquisitie (verzamelen en opslaan van gegevens). • Operator interface (grafisch). • Aansturing onderliggende controllers. • Alarmafhandeling.



1


6.7

Embedded netwerken (veldbus)


6.8

Embedded netwerken (controller bus)

Ongeveer 70 microcontrollers in een moderne automobiel Hogeschool Utrecht / Institute for Information & Communication Technology



6.9

Criteria bij veld en controller bussen • • • • • • • •

Controle, Event, Data Snelheid (real time) Prioriteiten systeem Betrouwbaarheid / robuustheid veiligheid Software / tools / platform Medium keuze Voeding distributie

6.10

Applicaties

• Aansluiting • Bereik • Standaardisering (leveranciers) • Behuizing / vormgeving • Onderhoud • Kosten




• Automotive (Abus, CAN, DIN, VAN) • Trein, metro en tram (Bitbus, DIN, WTB, IBIS) • Gebouwautomatisering (Batibus, CEBus, EIBus, Homebus, LON) • Procesautomatisering (Bitbus, CAN, FAIS, ISP, Profibus) • Aandrijftechniek (Drivecom, Encom, Profibus/DP, Sercos)

• Embedded systems (I2Cbus, CAN, Microwire, Open-Access Bus) • Sensor/Actuator (AS-I, CAN, Profibus/DP, Sensorbus) • Landbouw (DIN, LBS) • Overigen (Arinc, C-Mac, Midi, Mil-Std 1553, Batterybus)


6.11


6.12

Netwerk typeringen Toegang tot het medium

Communicatie over het medium

• Master / Slave relatie; wie neemt initiatieven (Single master / multple slave, Multiple master / Multiple slave ?) • Client / Server (request, response)

Pauze 15 minuten

• Producer / Consumer



2


6.13


I2C bus

I2C physical layer

• Designed for low-cost, medium data rate applications.

master 1

– 100 – 400 kbits/sec serial; multiple-master; fixed-priority arbitration. fixed addresses (7- or 10-bits, some reserved)

master 2

data line

SDL

• Characteristics: – – – –

6.14

clock line

SCL slave 1

slave 2

• Several microcontrollers come with built-in I2C controllers. Hogeschool Utrecht / Institute for Information & Communication Technology



6.15

I2C electrical interface


6.16

I2C data format +

Open collector interface: SDL

+ SCL “0” is dominant Hogeschool Utrecht / Institute for Information & Communication Technology



6.17


I2C data link layer

I2C bus arbitration

• Every device has an address (7 bits in standard, 10 bits in extension).

• Sender listens while sending address. • When sender hears a conflict, if its address is higher, it stops signaling.

– Bit 8 of address signals read or write.


6.18

(Collision Avoidance)


3



6.19

CAN Controller Area Network

I2C transmissions

(Bosch)

multi-byte write S

adrs

0

data

data

1

data

P

0

data

S

P

read from slave S

adrs

write, then read S

adrs

adrs

1

data

P


6.21

Producer / Consumer CAN Station 1 (Consumer)

CAN Station 2 (Producer)

CAN Station 3 (Consumer)

CAN Station 4 (Consumer)

Local Intelligence

Local Intelligence

Local Intelligence

Local Intelligence

Frame I

Filter

Filter

• Producer / Consumer model • Bus Arbitration (CSMA/Arbitration on Message Priority) • Remote Transmission Request • Deterministic (< 2 ms, real time) • Error Detection • Speed max. 1 Mbit/s (< 40m) • Cable length max. 10 km (5kb/s) • 128 nodes / subnet Hogeschool Utrecht / Institute for Information & Communication Technology


Filter

6.20


6.22

CAN frame

Filter

bus lines Hogeschool Utrecht / Institute for Information & Communication Technology



6.23

Bus Arbitration Method S R O Identifier T Control F 10 9 8 7 6 5 4 3 2 1 0 R Field

node 1


6.24

Profibus Data Field

listening only

node 2

listening only

node 3 recessive

bus-level

dominant

Node 3 wins arbitration and transmits his data. Hogeschool Utrecht / Institute for Information & Communication Technology


4


6.25

Opdracht • bestudeer hoofdstuk 16 Volgende keer geen les Tentamen: Een samenvatting van ten hoogste 2 kantjes A4 (niet inleveren!)


5

Netwerken in productiesystemen. Automatiseringspiramide SCADA. Inleiding computersystemen en netwerken deel 2

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