DE19615190A1 - Network-based control for industrial plants - Google Patents

Abstract

A network-based controller for industrial installations is in particular useful to replace a memory-programmable controller with a connected data processing system. To reduce local hardware requirements, the network-based controller (NBC) is connected by field busses, communication busses, an internal modem and an internet-compatible network connection to the data processing and process-controlling equipment of industrial installations. The controller uses the possibilities of distributed systems, in particular the performance characteristics of internet or intranet. The field bus connection and communication busses ensure the same performance as conventional control technologies. The software management of the network-based controller is adapted for internet and the technical processes are controlled by means of the field bus.

Description

The invention relates to network-based controls for industrial plants.

Such controls can be internal or external Computer networks, e.g. B. Internet, work together.

1. Terminology terms Internet

• I) Multiple packet switching networks using Help connected by bridges and routers are and communicate via protocols, so that it is a unified virtual network appear.
• II) A worldwide network run by the United States Ministry of Defense was called and the Transmission Protocol (TCP) and the Internet Protocol IP be uses.

JAVA

Object-oriented programming language, developed by SUN-Microsystems. JAVA compiler do not generate an INTEL processor code, but a special JAVA code. This code will on the target system of suitable JAVA-Inter pretern evaluated and on the respective target hardware translated. Meanwhile exist JAVA processors that already have this translation  take over on the hardware side. JAVA has meanwhile from all major software companies licensed (Microsoft, IBM, etc.).

Intranet

A local network is called an intranet net, which is the same physical and logical Has structure like the Internet. With intra nets can be fully internet compatible company internal networks can be set up at any time be connected to the official internet can. As with the Internet, the possibility used the network as a global fir to use cross-menu database.

Fieldbus

Fieldbuses are networks for connecting Central input / output modules in industrial Controls. You are not on the transfer large amounts of data. Rather serve on the rapid exchange of states Process level. Common fieldbuses are InterBus-S (PHOENIX), ProfiBus-DP (SIEMENS) and CAN bus.

Communication bus systems

To control (PLC, industrial computer, CNC etc.) to connect with each other, there is commu communication buses. They are physically so good specifies that data packets are directly addressed by ei control to one or more controls can be sent. In contrast to field buses are always on this protocol layer larger amounts of data sent. Everyone taxes The manufacturer usually offers to be  System-tailored communication buses with different price and performance form instructions.

PLC

Programmable logic controller: controller for the logical linking of process states. Mainly statement chains with fe Most cycle times processed sequentially.

2. Conceptual considerations 2.1 General basics

With the spread of the Internet, new perspectives. It is said ver the network as a global data concentrator and only use intelligent terminals access the databases. Such a terminal according to the manufacturer, only has a modem, the main memory, an operating system and the control unit (screen, keyboard and Mouse). Hard drives for data and program management no longer necessary. This is happening now directly on the network, the Internet.

In order not to unnecessarily increase the network load drive, trying to get information in as possible compact shape. The intelli interpreting browsers that are running on terminals the data (e.g. HTML) and prepare images from it and interactive menus, etc.  

With the programming language JAVA it is possible complex programs such as word processors, tables steering calculations, multimedia applications etc. whether to write object-oriented. Generate JAVA compiler hardware independent code. This must be from an In terpreter (or better from a JAVA processor) translated and evaluated on the user terminal will. All necessary for hardware control Program parts are therefore on the user terminal. Only the application itself is used in JAVA co sent over the net. Through this handle Exercise can be necessary for an application program Code can be broken down into two parts: a) Logical Program core and program flow structure, b) Building blocks for hardware control / administration. On the user terminal will only be in the future the second part. Program core, data and - Structures are loaded from the network as required.

On the other possibilities and services of the Internet will not be discussed in more detail here.

2.2 Extension to industrial control technology

In the field of industrial controls, too in addition to the conventional control functions more and more the functionalities of PCs, Networks and general data technology required.

Multimedia applications are also under control technology increasingly conceivable. Service instructions by Video clip, assembly pictures, maintenance instructions, Circuit diagrams etc. could be on the screen of the Machine control can be made available. As well  becomes the central capture of product related Manufacturing data over longer periods in the course ISO certification increasingly required.

Obviously a synthesis of the merits of modern communication technology with the need conventional control technology search.

2.3 Conception of the network-based controller (NBC)

An NBC is an intelligent participant in the Inter net or on in-house intranets. It has about all the skills and accomplishments of a modern Internet terminals. However, there is also a field integrated bus interface. The NBC contains, like all of them Internet terminals, no hard drive. The fieldbus can either be operated directly from the main processor or has its own controller. An embodiment of a network-based Control is shown in the drawing.

Advantages of this concept

• - Control program and multimedia application gen / network coupling run on the same Sy stem. When using an additional con trollers for fieldbus coupling are both sy steme even decoupled.
• - In the event of a voltage / network failure, the process can condition be secured.
• - Hard drives and vulnerable PC components (Plug-in cards) are basically not applicable.  
• - Without additional software expenditure can from the machine control on all da / pictures / applications on the Internet / intranet be gripped.
• - The actual control program (previous PLC program) can be downloaded via the network factory loaded.
• - Remote maintenance, program changes and data versions are easily possible via the Internet.
• - All manufacturing dates, downtimes, Shift protocols etc. are in the central network factory saved and can be further processed will.
• - Functionalities and services of the higher Programming languages can be found in the control pro grams can be used.
• - The permanently installed software on the NBC be is limited to a BOOT EPROM.

3. Physical structure of an NBC (Network-Based-Con troller)

Every intranet (Internet) subscriber (NBC) owns following hardware components:

• - Fieldbus connection (e.g. ProfiBus, InterBus, CAN)
• - Boot EPROM
• - main memory (RAM)
• - modem (ISDN or analog)
• - processor (possibly JAVA processor)
• - Internet / intranet compatible network interface tung
• - Screen / flat display / input devices  
• - Optional: Additional communication interface for fast direct connection (not via In ternet / intranet) between individual NBCs
• - SafeState system for network or voltage loss

3.1 Network-based controller (without additional con troller for the process periphery)

The fieldbus does not have its own in this form intelligent controller for constant time bear processing of process data. All process states must detected by the NBC processor via the fieldbus and be evaluated. Parallel operations on the internet / intranet can thus edit brake the process data. Even if the tax technical processes could be prioritized, is a decoupling of process control and possibly len multimedia applications not possible. NBCs the are only for non-time-critical processes applicable.

3.2 Network-based controller (with additional control process peripherals)

For the necessary decoupling from process control and multimedia application becomes an additional con troller switched on for autonomous fieldbus control puts. Via a shared memory or special mechanisms for data exchange can Process control and multimedia application internally communicate with each other.

Claims (9)

1. network-based control for industrial systems, in particular as a replacement for a programmable logic controller (PLC),
characterized in that the network-based de control (NBC n etwork b ased c ontroller) via field buses, communication buses, an internal Mo and the internet compatible Netzwerkan circuit in the data and process technology of industrial plants is integrated,
the control uses the possibilities of distributed systems, in particular the performance features of the Internet or intranet, so that the performance features of conventional control technology are fulfilled via the fieldbus connection and the communication buses,
the software of the network-based control is matched to the Internet and the control functionality via the fieldbus. 2. Control according to claim 1, characterized by:

• - Fieldbus connection for connecting the process periphery (sensors / actuators).
• - Boot EPROM. Mainly contains software for starting the NBC, for basic administration of the fieldbus periphery and for downloading programs from the networks.
• - main memory (RAM).
• - Internal modem (digital ISDN or analog).
• - Processor (especially JAVA processors).
• - Internet / intranet compatible network connection (with protocol TCP / IP).
• - Optional: screen / flat display / input devices (mouse, trackball, touchscreen, keyboard, electronic pen).
• - Optional: Additional communication interface for fast direct connection (not via Internet / intranet) between individual NBCs.
• - SafeState system in the event of network or voltage loss. The process data, which are read in via the fieldbus and result in a current process image, are saved in a non-volatile memory in a non-volatile memory.
• - Optional: Intelligent controller for autonomous management of the fieldbus without stressing the NBC processor.
• - Optional: Modules for multimedia applications (e.g. sound controller, video controller, MPEG, JPEG, graphic controller).

3. Control according to claim 1 or 2, characterized by:

• - Fieldbuses, through which the sensors / actuators are combined at decentralized locations and coupled to a central control system, where it is preferably an alternative to the bus system
• - is an InterBus-S (PHOENIX),
• - is a ProfiBus (SIEMENS),
• - is a CAN bus.

4. Control according to one of claims 1 to 3, characterized in

• that individual NBCs at different locations are directly connected to one another via a network,
• - That data packets are exchanged between the individual NBCs, and
• - That from an NBC memory areas of one of the other coupled to the bus th NBCs can be accessed.

5. Control according to one of claims 1 to 4, characterized in that via a modem and via analog or digital lines from an offi to the main telephone network whose computers can be set up. 6. Control according to one of claims 1 to 5, characterized in that a physical Interface on the NBC exists with the over the protocol TCP / IP accessed the Internet can be. 7. Control according to claim 6, characterized by:

• several packet switching networks, which are connected by means of bridges and routers and communicate via protocols, so that they appear as a uniform virtual network,
• - A worldwide network that was created by the United States Department of Defense and uses the Transmission Protocol (TCP) and the Internet Protocol IP.

8. Control according to one of claims 1 to 7, characterized by a local network (Intranet) which is the same physical and lo has a structure like the Internet, whereby with intranets fully internet compatible company tern networks can be built, each currently connecting to the official internet are, as with the Internet ge is used, the network as a global company to use a comprehensive database. 9. Control according to one of claims 1 to 8, characterized in that NBC software is provided,

• - which can be downloaded via network to NBC;
• - which can be used to access the complete Internet functionality;
• - whereby the NBC programs can run as JAVA programs;
• - Control programs, as they are known from the PLC, can run on the NBC and serve as a coupling to the process of the fieldbus, the control software being processed on an autonomous fieldbus controller;
• - Playable via the multimedia applications of the Internet.