Control Conversion

New Ammann system controllers for existing production systems

System controllers play an important part in the manufacture of asphalt, concrete and gravel mixes. They ensure that mixes are produced in accordance with standards and within the agreed time. Expensive stoppages are an inevitable consequence of controller failure, which is why a high degree of reliability, comprehensive support, retrofitting of additional system components, an uncomplicated user interface and rapid availability of service and spare parts are extremely important to system operators. If the controller supplier can no longer provide such service functions, the system operator is at considerable risk.

Ammann are well known as a leading manufacturer of asphalt production systems and can supply both new systems and a comprehensive range of individual components, which are used for converting and expanding systems made by Ammann and other manufacturers. Among others, these systems include mixers, filters, burners and metering equipment, and also system controllers. Ammann system controllers are the result of more than 80 years’ experience in systems engineering and 40 years of controller development. The following article relates to controller conversion in an asphalt system, but differs only slightly for concrete and gravel preparation systems.

Ammann controllers and control systems are operated via a graphical, flicker-free and clearly legible operator interface using a mouse and a keyboard, with current system status displayed in real time. The entire recipe-management system has a consistent design and is easy to operate. The system can be optimized during operation by adjusting parameters, while comprehensive password protection prevents unauthorized persons from making unwanted changes to the settings.

A comprehensive range of statistics and reports is an important tool at all levels within a quarrying company, from the machine operator and works manager through to senior management. Production data can be analysed according to batch, recipe and/or day, and shown in a graphical display. In addition, the integration of web tools makes it possible to access these analyses via the Internet.

Rapid, clear troubleshooting is extremely important, particularly when faults occur. To meet this need, the Ammann controller has many useful facilities, such as a bus diagnosis system, which allows faults to be localized and remedied without additional assistance. If a particularly persistent fault occurs, Ammann staff can access the controller via a modem and eradicate the fault.

The Ammann controller product range starts with conversion packages for weighing and mixing applications, followed by entire controller conversions. System controllers for concrete and gravel preparation systems, order scheduling and central scheduling systems, and the connection of several plants to form a multi-plant network, can also be realized using the same software platform.

The above-mentioned maintenance and support problems, and to a certain extent the age and complexity of operation of certain system controllers, may result in a decision to buy a new control system. During the evaluation phase it must be determined whether the new controller is just for the weighing and mixing process, or for the entire manufacturing process.

Restricting the new equipment to the weighing and mixing process may be particularly appealing from a financial point of view. System operators are provided with a solution that eradicates their problems in the weighing and mixing area with regard to operator interfaces, recipe handling, statistics and adherence to new standards. The new controller includes the operation and monitoring of the weighing and mixing process, while the rest of the system continues to be operated with the existing controller.

However, if the current controller problems are not restricted to the weighing and mixing process but extend to other parts of the system, it might be worth considering a full controller conversion. This may or may not require modifications to the loading components. The following distinction can be made:

• Replace the existing loading components if the assessment of these components reveals that they cannot continue to be used. The reason for this usually lies in the age of the loading components and the associated lack of spare parts, together with a lack of reliability.
• Recently it has been found that older components can meet today’s requirements with few concessions. In these cases a bus system interface is installed in the existing loading components.

The duration of a conversion largely depends on whether all of the loading components are going to be replaced or an interface is going to be installed. Practical experience has shown that a controller replacement, including installation and wiring the interface to the existing loading components, can be carried out in 3–5 days.

Ammann place great value on comprehensive support after the completion of a project, with trained staff and a comprehensive stock of spare parts on hand to ensure customers’ problems are dealt with quickly and reliably. In addition, the Ammann help desk can be contacted if difficulties occur, and experience has shown that the majority of problems can be quickly solved via remote access. The modem connection can also be used to load software updates.