Codesys sp for windows nt realtime

Realtime Runtime System for Windows NT/2000/XP

Document Version 2.2

CONTENT

1 Overview 3

2 Operation via the
Service Icon 5

3 The 3S Standard IO
Drivers 14

4 Communication 22

5 System Diagnosis 23

6 The Task Configuration
together with CoDeSys V2.3 25

7 Behaviour in case of
runtimeerrors 30

8 APPENDIX 31

Change History 34

1Overview

In
this document it is assumed that the reader is familiar with the
fundamental behaviour and functions of a CoDeSys runtime system.
Therefore this brief manual only deals with the specific features of
the runtime system for a real time extension of Windows NT.

The
real time system is started by executing the command ‘Start CoDeSys
SP Windows NT for Realtime’ in the CoDeSys menu in the Windows
Start menu. When started the following service icon
appears in the Windows task bar:

1.1What does «real time extension» mean?

A
real time system is characterized by predictable (deterministic) time
behaviour. If for example a real time system is given the task of
executing specific routines (through configuration) within a
predetermined time pattern this will happen within predetermined
temporal ranges of tolerance. If this is not the case it is regarded
as a failure of the whole system.

If
this is applied to a controller such as CoDeSys this means that a
task is called within predetermined (known) ranges of tolerance.

Figures
drawn from past experience have shown that these ranges are not
adhered to by Windows NT, which means that NT is not a genuine
realtime operating system.

Yet
the hardware in a PC is made in such a way that it is possible to
create a reliable task scheduling by means of software.

The
real time extension of Windows NT is an NT driver which installs an
Interrupt-Service-Routine which is called-up cyclically by the
timertick of the PC’s hardware.

This
routine now takes over the job of calling-up defined tasks from
CoDeSys and/or of authorizing the continued or renewed execution of
the operating system.

1.2The System in Detail

Картинка с сайта: studfile.net

The
kernel of the realtime extension (short RTE) consists of two parts: A
system service, called RTService.exe and a kernelmode-driver
(3SRTE.sys). In standard version the PC’s timertick is used to
generate 2 hardware interrupts per millisecond, and so call the
scheduler of the RTE. The scheduler uses every second tick to call
his own tasks and the others to return to the interrupted OS. So all
PLC-tasks are interrupted once per millisecond by a time slice of
OS-execution. The percentage of time for PLC-tasks is configurable
(see chapter 6).

The
mentioned IO-drivers are added to a list and have to offer a special
interface which is defined by the IO-DriverToolkit.

The
whole system does not change the operating system’s kernel at
runtime or installation.

2Operation via the Service Icon

See
the user menu (right mouse button) of the RTE Icon in the task bar:

The
commands which are available, depending on the current operational
status, are shown black-colored (enable).

The
following individual operations can be conducted:

• Start
  System loads and activates the driver.
  Only then is it possible to work on real time tasks and to
  communicate with the programming system.

• Stop
  System stops the driver and removes it
  from the PC’s memory.

• Start
  Cycle / Stop
  Cycle start and stop the cyclical
  execution of IEC tasks. This operation corresponds with the menu
  item «Start»/»Stop» in the online menu of
  CoDeSys.

• Next are
  the three types of Reset
  options which also correspond with the entries in the CoDeSys menu.

• About
  shows the splash screen of the RTE which apart from the icon also
  includes information on the version and the copyright.

• System
  shows a dialogue with system settings. Two settings can be altered
  here: If there is a tick behind the option “Start
  when booting“ the service will be started automatically by NT on
  the next start of the system. This happens completely regardless of
  the fact whether a user logs in or not. With the option “Automatic
  PLC Start“ the user can decide whether to start the driver
  automatically from the service or not.

• Exit
  not only stops the driver but also the service after the driver has
  been unloaded. The service can be restarted with “Start –
  Settings– System Control – Services“ or by the entry in „Start
  – Programs“ under CoDeSys. It is possible to start the driver in
  “System Control – Devices”, yet this is not very sensible
  because it deactivates the driver. The RTE service activates it when
  starting.

• License
  is only available, if you own a newer version, where the hardlock
  (dongle) is replaced by a software license.

Соседние файлы в папке IODriver ToolKit

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  11.10.20201.36 Кб21CardFunctions.c

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  11.10.20201.01 Кб21CardFunctions.h

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  11.10.202018.65 Кб22IOdrvFunctions.c

• #

  11.10.20206.88 Кб21IODrvFunctions.h

CoDeSys Control — это часть, которая должна быть встроена в ПЛК. Программируя ПЛК, пользователь должен думать исключительно о сути прикладной задачи. Его не должны волновать организация памяти, процедуры опроса модулей ввода/вывода, способы синхронизации данных, функции сетевого обмена и связи с верхним уровнем, вызовы циклических и событийных задач, организация фиксации выходов при отладке на оборудовании и т. п. Всю черновую работу за него должна выполнить система исполнения.

В общей сложности CoDeSys Control включает более 200 компонентов. Каждая «сборка» под конкретную модель ПЛК будет отличаться. Ее состав определяется возможностями аппаратуры и типом ПЛК. Включение абсолютно всех компонентов, на всякий случай, привело бы к неоправданному росту аппаратных ресурсов и стоимости.

Например, включение функции «горячей» правки кода без остановки ПЛК удваивает требования к ОЗУ.

Некоторые компоненты представлены в нескольких вариантах. Например, компонент «менеджер задач». Самый дешевый ПЛК может иметь единственный аппаратный таймер, «тикающий» каждые 10 мс, и не иметь ОС. Для него подойдет простой планировщик циклических задач без вытеснения. С ним не смогут работать некоторые другие компоненты, например, ЧПУ или стек CANopen, но они и не требуются в ПЛК такого уровня. Для ПЛК с мощным 32 — или 64 — битным процессором и ОС РВ разумно включить наиболее совершенный «менеджер задач» с поддержкой событий, реального времени и нескольких приложений в одном устройстве. С каждым таким приложением можно работать как с независимым ПЛК: загружать, запускать, останавливать и отлаживать программы, не влияя на работу других приложений.

CoDeSys Control может функционировать под управлением любой ОС или даже без нее. Наиболее часто используют ОС VxWorks, Windows CE и Linux. Имеются адаптации под RT — OS32 (RTKernel), QNX, Nucleus, pSOS, OS9, TenAsys INtime. Изготовитель оборудования может самостоятельно адаптировать CoDeSys Control под другую ОС.