The ABC- Computer Network, a product of the Fuhse GmbH Product survey, network specification, recent developments, and experiences of customers. We are one step nearer to the future.

Every unit is - by implanting the programmed network operating system - extremely skilled for the network dialog:

If one unit wants to send a message - say "the limit level of a process state in the plant is reached" - to the central computer, it first observes the state of the bus line. It patiently waits, till the bus is free, and, of course, the other units are polite enough, to terminate their dialog as quickly as possible. So, when the bus is free, the unit puts a message on the bus: "My priority is P, I want to call unit AB, my name is XY, and I want to send a standard message". This message, of course, is coded. It reads "PABXYN", where P stands for priority, AB for the address of the computer, XY for the own address, and N for normal message.

This message is codes serially and asynchronously. The coding follows just standard RS-232-C encoding, except of the fact, that the signal is inverted (this has important practical reasons due to increasing the system reliabilty).

When the unit "AB" is listening to the bus, it will send an "R"- message (Ready) back. Only then, the message will be delivered, flanked by a number of checks to encertain that all data are correct.

Generally, this whole transfer of date takes place within 100 milli- seconds. This is a long time as compared to todays standards in office communication. But please consider, during this time, many checks have been made. And, most importantly, the system allows to garantee that the message passes within this time. The whole system is a "real time system".

The reason for this extreme network safety and reliability of the ABC computer network is, that the units observe the bus, while the data transfer takes place. Even the two units, who actually do the communication, observe very carefully, what is happenen on the bus, while putting the data on the bus. E. g. if two units are - by accident - sending simultaneously, the unit with the lower priority will realize that a high priority message is on the bus; it therefore will retreat without having disturbed the high priority message.

This is a very important item of the ABC- system: in fact, two or even more units, who happen to send a message at the same time, will sort out, who is going to proceed, without having disturbed the message of this one unit. Therefore: if there is a collision of data, there is always one unit left, which may proceed, - even, if one of the other units has the same priority. And the system makes shure that this one message will not be disturbed an can reach the addressee freely.

This is one of the most important particularities of the ABC- computer network, and it makes the ABC- computer network unique as compared to all other field busses. It allows for perfect data transmission, even if two or more units try to access to the bus simultaneously. Of course, further methods, as to randomly accessing the bus after the end of another dialog, etc. ease data traffic even more.

Network nodes with computer interface:

Easy computer interfacing to the network is made using the network interfaces with RS-232-C connection.

These units are used for interfacing all sorts of computers, printers, even CNC- drilling machines etc. to the network.

A difference is made between thump devices as printers, which allow just for the raw data to be transferred to the printer, or computers, which - in most cases - will also be given additional information as to the sender´s address and the command. This information is used to reassign the information to the individual ABC- units. Thereby the computer can evaluate the information and develop strategical methods as to how to cope with the new situation.

Of course, the way, how the information is processes, is depending on the individual application of the customer.

Terminals for data acquisition:

Manual data acquisition within a factory or a plant, even in offices, is made using these terminals with built in LCD- Display and keyboard.

Additionally, the terminal can be equipped with bar code readers, magnetic card readers or even chip card read/write- systems. Furthermore, the terminals may have a built in vocoder, thereby transferring ASCII- data to speech (with English- and German pronounciation).

The terminals are developed to make data acquisition as simple and as clean as possible. Although the terminal is just as large as a keyboard (even a bit smaller than th standard PC- keyborad), it provides a complete interfacing system on the working place, which otherwhise would be covered by CRT- screens and periphery, thus obscuring the workers sight from the essential things - his works.

Terminals for time control:

These 2003- terminals are of fixed wall type with water protection according to IP65. The terminals may be equipped with built in magnetic card reader, chip card reader, bar code reader, and many more.

For external uses, a built in heater is also available, insuring that the terminal will work at extreme frost.

Power supply with built in network device:

The terminals have either a built in power supply or an external power supply. The units in the picture combine power supply with a network interface; thereby the terminal becomes a very clean and simple system, because the keyboard/display housing has just one cable. This allows for a very clean setup of the working place.

The units depicted do also include a galvanic decoupling of application side and bus side. Galvanic decoupling is made employing opto- couplers.

Environmental control station:

Environmental control can easily be made with the ABC- computer network, because the network cable allows for long distances between metering station and computer. Our company has set up an environmental control station with built in data logger, A/D- converters, event monitor etc. Thereby data acquisition of all sorts of environmental data can be made very simple.

Mass- Spectrometers interface:

Interfacing mass spectrometers of the popular Balzers mass spectrometers has been accomplished with this unit as developed by our company. The unit directly controls the ranges of masses to be monitored by the mass spectrometer, and the unit transfers the data to the computer. The computer may simultaneously control several mass spectrometers, and - at the same time - control even more units.

Our company has set up a PC- program, which does all that. The program is available for DOS- applications as a stand alone system. It can also be made available as a Windows 3.X- application or for Windows95, thereby ensuring free use of the computer for additional tasks.

Industrial control unit FX1:

An industrial control unit has been set up with direct network interfacing. There are many new features in this unit, as the internal bus- system, which allows for easy extension up to 64 additional interface cards, as the ability to be extended to a multi- processor system using the newly developed cockpit computer system, and as low power consumption and internal watch dog device.

The unit in this picture has 4 digital I/O- cards, a built in A/D- converter with 64 channel multiplexer and other peripheral interfacing devices.

The lower part of the picture shows a slide away terminal for 19 "- rags; this terminal is a separate ABC- unit and controls the FX1- unit via the ABC- bus.

Time controlling system:

Time data acquisition has beome an important application of the ABC- computer network. Thereby the Time control terminals can be widely distributed all over the factory or the company´s site. Staff members can us magnetic cards or chip cards for easiness of data input. In some cases, people use ID- cards with bar codes or just a personal key number.

Production controlling:

Similar terminals are used for production controlling. The advantage of the system is to keep ways as short as possible.

With this system, many companies have improved the flexibility of their production. Instant information about production scheduling, quick response, if any disturbance occurs, and many more advantages make this concept advantageous for production and storage. Of course, there is no ready made system for all applications. Hardware installation must be flanked with an organisational scrutiny and the setup of a data evaluation and handling system.

There is no standard system. However, our general networking software (running under DOS, Win3.X or Win95) can, in many cases, be used as basic building brick of a complete system.

Large electric current contol units:

The depicted unit controls electric currents of up to several Amperes with direct network interface.

The picture shows in the top box a slide away terminal for 19"- rag mounting. The centre unit is the FX1- industrial control system. The bottom unit contains the high current output unit as used by a customer for controlling some physical chemical process.

Clean Desk top with Fuhse 2002- terminals:

A clean terminal for easy data acquisition

Clean desk top and complete data acquisition is accomplished with the 2002 terminals. As the pictures show, the desk is minimally occupied by the terminal, and just a thin and flexible cable connects the terminal to the power supply, which also contains the network interface.

Environmental control system for petrol industry:

Data acquisition in a petrol chemical plant requires some precautions due of explosive gas hazards. The electronic part of the environmental control unit is completely encapsulated in an EX- protected housing, and just the metering sensors are exposed to the air.

Time data controll system:

Complete Time data control system have been developed by the Fuhse GmbH. This system - initially called FESZEIT - provided time control for about 200 workers. Recent developments allow for several thousand workers with flexible working hours.

The system runs on standard PCs. Programme versions are available for DOS, Windows 3.X or even Windows95.

The picture shows the presence- board in a company with 160 staff members. Windows95- versions of the programme allow for the presence indication of some 700 staff members on one screen. The states are indicated in different colours, according to "presence", "on leave", "break", or "out of house". Modern monitors with their large variety of colors allow for even more status indications.

Peripheral control system:

Low costs of the enviromental control system and extreme reliability allow for the remote installation outside the companies site.

Direct network interfacing with CNC machines:

This picture shows one of the first installations of the ABC- computer network at "PL Präzisions- Leiterplatten GmbH" (now "Straschu Leiterplatten GmbH"). The Network node interfaces the drilling machine via a standard RS 232 C- connection to the network. A cental computer thus controlled all CNC- machines and even the R&D- department was included in the network.

Industrial robot control:

Our company developed various robot control units, and even an own robot development was initiated for a 6 axis industrial robot. R&D war particularly made simple by the network interface, allowing for instant control of the movement; furthermore it was possible that one computer initiated the movements and a second computer monitored the correctness of the movement, directly using the same data.

The picture shows two robots working on the same piece. This is only possible, when close networking of two robot controls nearly makes them appear as one unit.

Complete systems for networked production:

Interfacing CNC machines with a central computer is just one task in organizing and automating a factory. Another part is the set up of a computer programme. Before that, a careful scrutiny must be made of the organisation and the structure.

In accompaniing our customers, which mostly set up their production system themselves or by external systems programmers, our company gained the experience as to how a complete system has to be installed and will eventially work.

Intelligent sensors with direct network interface:

Further miniaturisation of our microcomputer systems led to a number of intelligent sensors with a direct ABC- Network interface.

These comprise:

- radioactive sensor using Geiger- Mueller- Counters
- dielectric sensor for humidity and moisture in food and other solid substances
- nuclear magnetic resonance sensor for sensing elementary abundances and magnetic properties.

This latter NMR- sensor allows also to determine to some extent physical- chemical properties, because the narrow resonance lines of the NMR- spectra are broadened by various effect, thus allowing for indirect metering systems of all sorts of quality quantities. These, as the NMR- systems in human medical application, have the advantage of non destructive metering.

Fuhse 2001 terminals with magnetic card reader:

The recent versions of the 2001 terminals have clean housings, they include magnetic card readers, and they have a built in data- logging and processing capability.

The units are equipped with the ABACOS- operating systems (Asynchronous Bus Application Control Operating System). This is a specially devoloped operating system, which gives the terminals a multi- user /multi- tasking capability. Up to 40 programmes can simultaneously run in the terminal.

This allows the terminal to work as a stand alone unit, as long as the central computer is not available. As soon as the central computer (main network node) becomes available, the terminal will send the stored data.

Fuhse 2002 terminal with bar code reader:

The terminals have a built in bar code reader for 2/5 i- bar codes. This allows for easy data acquisition, in particular for production planning and control, for quality assurance systems and many more.

The picture shows that the bar code reader fits nicely to the terminal and still leaves the working place clean.

We can be reached by E- Mail "fuhsenet@wilmar-fuhse.de" zu erreichen

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(c) Fuhse GmbH 1997
date of last issue: 3. 4. 1997