What is Profibus

1
Profibus - Alice RCU - Bergen, November 11, 2002
Jon Wikne
What is Profibus?
PROcess FIeld BUS. An open bus standard,
originally developed for industrial
automation and process control. Standard
documents IEC 61158, EN 50170, DIN 19245.
Is Profibus the same as Fieldbus?
Profibus is an international standard of European
origin, similar to and using concepts from
Foundation Fieldbus, but not identical.
What is the impact of Profibus with the ALICE
detector?
It might be used for some of the slow controls of
the readout system, for instance for the TPC.
Who supports Profibus, and what products are
available?
Several companies offer products ranging from
Profibus ASICs to complete systems.
1
2
Profibus - Alice RCU - Bergen, November 11, 2002
Jon Wikne
The protocol architecture of Profibus
is based on the OSI (Open System Interconnection)
model, according to the ISO 7498 standard. Three
flavours DP (Decentral Peripherals)
FMS (Fieldbus Message
Specification) PA
(Process Automation)
Physical layers of Profibus
RS485, twisted-pair cable (most common
implementation) IEC 1158-2, twisted-pair
cable Fibre optics
General characteristics of Profibus
Data rates Up to 12
Mbits/s Cable length 1200m
/ segment up to 100 kbits/s, 100m at 12
Mbits/s Cable type (RS485) Type-A,
135 -165 W characteristic impedance, lt
30pF/m Communication technique Master/slave,
Peer-to-peer. Media access method Token
passing. Number of nodes / network Up to 127 (32
per segment).
2
3
Profibus - Alice RCU - Bergen, November 11, 2002
Jon Wikne
Protocol and Layer Overview
3
4
Profibus - Alice RCU - Bergen, November 11, 2002
Jon Wikne
RS-485 cabling and termination
4
5
Profibus - Alice RCU - Bergen, November 11, 2002
Jon Wikne
5
6
Profibus - Alice RCU - Bergen, November 11, 2002
Jon Wikne
Profibus PCI Card Example, Hilscher CIF 50-PB
The card runs OPC (OLE (Object Linking and
Embedding) Process Control) server software
6
7
Profibus - Alice RCU - Bergen, November 11, 2002
Jon Wikne
Use of Profibus-DP in the ALICE TPC RCU/RORC
concept
Employs a Profichip VPC 3 B Intelligent Slave
chip on a mezzanine card This chip handles
Profibus communications, and interfaces to a mP
(mC) bus. In the present system, this bus
interface will be implemented as part of a FPGA.
VPC 3 B highlights Integrated 4kB
Dual-Port RAM Multiple mC operation modes
(Intel, Siemens, Motorola) Handles DP
Slave Protocol Programming and status
registers Interrupt Controller
Watchdog Timer Microsequencer
UART (Universal Asynchronous Receiver /
Transmitter)
7
8
Profibus - Alice RCU - Bergen, November 11, 2002
Jon Wikne
8
9
Profibus - Alice RCU - Bergen, November 11, 2002
Jon Wikne
VPC 3 B Experiment Card set
9
10
Profibus - Alice RCU - Bergen, November 11, 2002
Jon Wikne
Profibus RS-485 cable with switchable terminator
plugs
10
11
Profibus - Alice RCU - Bergen, November 11, 2002
Jon Wikne
In the final version, the VPC 3 B chip must be
interfaced to the FPGA. Two possible
approaches 1) Implementing a complete
microcontroller core (80C81, 80X86, 80C166,
C501 or HC11 type) 2) Implementing the required
subset of control sequences as state machines.
11
12
Profibus - Alice RCU - Bergen, November 11, 2002
Jon Wikne
Conclusion
At this stage, there isn't one....
12
13
Profibus - Alice RCU - Bergen, November 11, 2002
Jon Wikne
14
Presentation for NFR - October 4, 2001 - Trine
S.Tveter
15
Presentation for NFR - October 4, 2001 - Trine
S.Tveter