Спецификация протокола Profibus

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PROFIBUS-Specification-Normative-Parts-8:1997

14.1 General............................................................ 865

14.2 Format of the Device Data Base File................................ 865

14.3 Meaning and Coding of the Key Words................................ 866

14.3.1 General............................................................ 866

14.3.2 General DP-Key words............................................... 866

14.3.3 DP-Master (Class 1) related Key words.............................. 868

14.3.4 DP-Slave related Key Words......................................... 872

14.3.5 Formal Description of the DDB-File Format.......................... 874

14.3.6 Examples for DDB-File Entries...................................... 878

15 Application Characteristics........................................ 880

15.1 Restrictions....................................................... 880

15.2 Time Behaviour..................................................... 880

15.3 Manufacturer Identifier............................................ 880

Annex 2-B (normative) ....................................................... 881

Mixed Operation ............................................................. 881

2-B.1 Mixed Operation of FMS- and DP-Devices on the same Line............ 881

2-B.2 Mixed Operation of DP and FMS in the same Device................... 882

2-B.2.1 General............................................................ 882

2-B.2.2 Configuration Instructions for Composite Devices................... 883

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1 Field of Application and Purpose

The PROFIBUS Specification comprises a great variety of functions and allows for

a wide range of applications. This includes cell communication between powerful

controllers as well as interfaces to field devices.

Part 2 to Part 4 define media access and transmission control (Data Link Layer,

Layer 2 of the OSI Layer Model, see also DIN 7498) and Physical Layer (Layer 1).

This parts of the specification are independent of the application layer

functions.

Part 5 and Part 6 define the application layer (Layer 7) functions of this

fieldbus specification. This Specification is similar to Manufacturing Message

Specification MMS (DIN ISO 9506) and thus makes interfacing to MAP networks

(Manufacturing Automation Protocol) feasible.

Part 2 to Part 7 are required in applications that need the high functionality

of FMS services and interfacing to MMS.

Applications in the area of decentralized peripherals that do not need the pow-

erful services of FMS but require extremely short system reaction times should

use the solution presented in the following paper. The well known properties of

Part 2 to Part 4 of this specification are used in combination with a very

efficient User-Interface. Thus PROFIBUS-DP expands the sequence of PROFIBUS

Standards for this specific application area.

The following definitions describe the necessary functional and electrical prop-

erties to manage peripheral devices connected through a serial interface to

e. g. a controller in manufacturing applications. This specification describes

an abstract model but the real form of an implementation will be not fixed by

this specification. Part 2 to Part 4 are used as physical and data link layer

and extends its definitions to fulfil the special requirements in the area of

remote peripherals.

Decentralized Peripherals (DP) are mainly used to connect automation systems

(such as programmable controllers) via a fast serial link to input-/output-

devices, sensors, actuators and to smart devices.

The main purpose of PROFIBUS-DP is the fast cyclic exchange of data between a

powerful Master (automation system) and several simple Slaves (peripheral

devices). Thus, this system uses mainly the Master-Slave-type of communication

services.

The hybrid media access of PROFIBUS allows Master-Slave communication as well as

Master-Master communication, which is used for Data transfer between DP-Master

(class 1) and DP-Master (class 2)(programmer/diagnostic-panel).

In applications that do not need the maximum speed, a combination of PROFIBUS-DP

with PROFIBUS-FMS on the same network is possible.

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2 Normative References and additional Reference Material

DIN 41 652 Teil 1 Steckverbindungen in der Nachrichtentechnik;

(draft) Steckverbinder für die Einschubtechnik,

trapezförmig, runde Kontakte 1 mm

DIN 66003 Informationsverarbeitung; 7-Bit-Code

DIN 66 259 Teil 3 Elektrische Eigenschaften der Schnittstellen-

leitungen; Doppelstrom, symmetrisch,

bis 10 Mbit/s

DIN EN 61131-2 Programmable Controllers-Part 2:

Equipment Requirements and Tests

DIN EN 66306 Industrielle Automation und Integration; Fest-

Teil 1 legung der Nachrichtenformate für Fertigungs-

zwecke; Definition der Dienste; Identisch mit

ISO/IEC 9506-1:1990

DIN ISO 2375 Datenverarbeitung; Verfahren zur Registrierung

von "Escape-Sequenzen"

DIN ISO 7498 Informationsverarbeitung, Kommunikation Offener

Systeme; Basis-Referenzmodell

EIA RS-485 Standard for electrical Characteristics of

Generators and Receivers for use in balanced

digital Multipoint Systems 1)

1) Source of Supply for DIN Standards:

Beuth Verlag GmbH

Burggrafenstr. 6

D-10787 Berlin

Germany

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PROFIBUS-Specification-Normative-Parts-8:1997

3 Abbreviations

AD Access Denied

ASIC Application Specific Integrated Circuit

CNTR Control Signal

DDB Device Data Base

DGND Data Ground (PHY, RS-485)

DI Data Incomplete

DP Decentralized Peripherals

DS Disconnected Station

local FDL/PHY controller not in logical token

ring or disconnected from line

EA Area too large (Up-/Download)

FDL Fieldbus Data Link

FE Format Error in a request frame

FMA Fieldbus Management

FMS Fieldbus Message Specification

GAP Range of station addresses from this station to

its successor in the logical token ring

IP Invalid Parameter

IV Invalid parameters in request

LE Data area length too large (Up-/Download)

LLI Lower Layer Interface

LSAP Link Service Access Point

identifies one FDL User in a particular station

L_sdu Link_service_data_unit

NA No Acknowledgement, no reaction from remote station

NC Master parameter set not compatible

NE Area at responder not available

NI Function at responder not implemented

NO Service in this state not possible

NR No Response Data

OK Service finished according to the rules

PDU Protocol Data Unit

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PROFIBUS-Specification-Normative-Parts-8:1997

PHY Physical Layer

PLC Programmable Logic Controller

PNO PROFIBUS Nutzerorganisation

Pulldown Resistor

RE Format Error in a response frame

RR Resources of the remote-FDL entity not

sufficient or not avaiable

RS Service or remote-address at remote-LSAP

or remote-LSAP not activated;

- remote-station is no DP-Station

- remote-station is not yet ready for

these functions

- remote-station is associated with an

other Requester

- optional service not available

Termination Resistor

Pullup Resistor

RxD Receive Data signal (PHY, RS-485)

SAP Service Access Point

SC Sequence Conflict; Function in the actual operation

mode not allowed

SE Sequence Error

TO Function-Timeout expired

TxD Transmit Data signal

UE Remote DDLM/FDL interface error

VP Voltage-Plus

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4 Terms

Table 1. Terms

Access Protection The master access to a DP-Slave is disabled

for other DP-Masters.

Address-assignment-table List in which, as an Example, the PLC-

addresses are assigned to the decentraliced

inputs and outputs.

Blocked data transfer The data-range that should be transferred is

transmitted in several blocks (parts).

Bracket data transfer A data transmission is bracketed by a start-

sequence and an end-sequence. Inside this

sequence, the access of any other DP-Master is

disabled.

Channel Input- or output-data-range of a DP-Slave.

Width: One bit up to a double word.

Channel related Diagnostic Lowest level of slave specific diagnostic. The

diagnostic information refers to a single

input or output channel of the DP-Slave.

Composite-device A device that provides PROFIBUS-FMS and

PROFIBUS-DP services.

Configuration In the start-up phase, the DP-Master (class 1)

transmits the expected configuration for

comparison with the real configuration to the

DP-Slave.

Configuration error If the DP-Slave detects a difference between

the expected configuration and the real

configuration, an error-flag is set in the

diagnostic-information.

Coherent data range The input- or output-data-range that always

shall be transmitted coherently between the

DP-Master and the DP-Slave.

Control Commands Control commands will be transferred from the

DP-Master to the DP-Slave. With the control

commands it is possible to clear the outputs,

or to freeze the inputs and/or outputs of a

single or many DP-Slaves.

Control timers - An adjustable control timer of the DP-Slave

to detect a breakdown of the assigned DP-

Master.

- An adjustable control timer of the DP-Master

(class 1) for monitoring the user data

exchange mode with the corresponding DP-

Slaves.

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DDLM The main task of the Direct Data Link Mapper

(DDLM) is the mapping of the functions that

are called at the interface to the User-

Interface, on the FDL- and FMA1/2-services,

see section "Protocol Architecture".

Decentralized Peripherals Input- or Output-devices that are connected

via a fast serial link with the central

controller.

Default-Address In case of the initial-clear of a DP-Slave, it

changes its address to the address 126.

Device related Diagnostic Highest level of the slave-specific

diagnostic. The diagnostic information is

related to the whole slave.

Diagnostic Buffer A register that is able to store the

diagnostic information temporarily.

Diagnostic Information

Collection

A system-diagnostic information that is

collected at the DP-Master (class 1).

Diagnostic Information The status- or error-messages that are present

at a DP-Master (class 1) or DP-Slave.

DP-Master (class 1) The DP-Master that polls the assigned DP-

Slaves and handles the user data exchange.

DP-Master (class 2) The DP-Master that interacts as a

configuration or diagnostic tool; usually a

programming device.

Expected Configuration Same structure as Real Configuration. During

the start-up phase, the DP-Master (class 1)

shall transfer this information to the DP-

Slave for comparison.

Freeze inputs or outputs An update of the inputs or outputs will be

made. This state remains until the next

control command will be received.

Grouping DP-Slaves can be gathered into groups.

Identifier For each input- and/or output-range of a DP-

Slave an Identifier-byte is defined in the

configuration phase.

Identifier related Diagnostic Medium level of slave specific diagnostic. The

diagnostic information is related to the

input- or output-range for which a related

Identifier-byte is defined in the

configuration phase.

Master Parameter Set The master parameter set includes the

configuration and parametrization data of all

DP-Slaves that are assigned to the

corresponding DP-Master and the general bus

parameters.

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Mixed-Mode PROFIBUS-FMS and PROFIBUS-DP devices are

operating simultaneously on the same

transmission medium.

Real Configuration The amount and the width of the input- and

output-data-ranges of the DP-Slave.

Additionally, the description of the data

consistency is included in the real

configuration.

Reset A hardware or software initiated resetting of

a DP-Slave.

Scheduler Controls the sequence of actions in the DP-

Master (class 1).

User-Interface The User-Interface represents in the layer

model the interface to the user.

Vendor Identifier This identifier specifies a DP-Slave type. It

is administered and allocated by the PNO.

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5 Requirements on the PROFIBUS-DP System

To switch from peripherals plugged in a controller to remote inputs/ outputs a

fast data link is necessary not only for the exchange of process values, but

also to transmit diagnostics, configuration data and parameters.

This application requires a communication system with short reaction times.

Table 2 gives an overview of the requirements and features of PROFIBUS-DP

system.

Table 2. Requirements and Features of PROFIBUS-DP

+------------------------+-------------------------------------+

! Requirement ! Feature of PROFIBUS-DP !

+------------------------+-------------------------------------+

! Short reaction time ! Exchange of more than 1000 Inputs !

! ! and Outputs with 32 devices in less !

! ! than 10 ms. !

+------------------------+-------------------------------------+

! Monomaster or Multi- ! Hybrid media access according to !

! master Operation ! PROFIBUS !

+------------------------+-------------------------------------+

! Simple protocol, ! reduced functionality of PROFIBUS !

! low cost communication ! ASIC solution without !

! interface ! microprocessor support !

+------------------------+-------------------------------------+

! Proven transmission ! Hamming Distance 4 guaranteed !

! technology ! in a PROFIBUS system !

+------------------------+-------------------------------------+

! Excellent diagnostic ! Various diagnostics in Masters !

! ! as well as in Slaves !

+------------------------+-------------------------------------+

! Simple User-Interface ! Basic set of parameters and !

! ! configuration data !

+------------------------+-------------------------------------+

! Use of existing ! PROFIBUS FMS- and DP- devices !

! cabling and test ! can operate on one network. !

! equipment ! Same technology of transmission in !

! ! all applications !

+------------------------+-------------------------------------+

! Interoperability ! Precise and complete definitions !

! ! inclusive the definition of the !

! ! system behaviour. !

+------------------------+-------------------------------------+

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6 Behaviour of the System

6.1 General

In a typical remote I/O configuration single master configurations are mainly

used to fulfil reaction time requirements. In lower speed applications

multimaster configurations are also possible. PROFIBUS-DP uses the polling

principle for communication (Master-Slave method). This means a DP-Slave station

needs a Master-request to exchange information. The message transfer is

organized in cycles. A message cycle mainly consists of a request-frame of the

active station followed by the corresponding acknowledgement/response-frame of

the addressed station. An exception to this is the global-control function for

syncronization and coordination of several remote I/O stations.

A PROFIBUS-DP system consists of several communicating units. These may be DP-

devices or devices working according to the FMS protocol of PROFIBUS.

Several station types can be identified:

- DP-Master (class 1)

- DP-Master (class 2)

- FMS-Master

- DP-Slave

- FMS-Slave

DP-Master (class 1):

This DP-Master controls several DP-Slaves according to a well defined algorithm.

The DP-Master (class 1) uses the PROFIBUS-DP functions to communicate with DP-

Slaves.

The DP-Master (class 1) polls the associated Slaves to submit data to its local

user. The DP-Master (class 1) can communicate to a DP-Master (class 2) by a set

of functions. This means a DP-Master (class 1) acts both as requester and

responder.

DP-Master (class 2):

In a PROFIBUS-DP system a DP-Master (class 2) is a programmer or a management-

device. A set of functions supports management and diagnostics of a complex DP-

system.

The local user of the DP-Master (class 2) defines which operation has to be done

depending on the kind of service required and which station has to be addressed.

FMS-Master:

This is a Master that communicates according to the rules of PROFIBUS using the

FMS protocol.

DP-Slave:

A DP-Slave can be addressed by both types of DP-Master. This DP-Slave implements

a defined set of responder functions.

FMS-Slave:

This defines a type of Slave that communicates according to the rules of

PROFIBUS using the FMS protocol.