ifm: AS-Interface Enhances Efficiency and Flexibility in Silos
May 6, 2025
AS-Interface enhances Efficiency and Flexibility in Silos
Companies worldwide are relying on simple wiring and automation technologies to improve plant efficiency and availability. The proven AS-Interface technology offers high reliability, noise immunity and comprehensive diagnostic capabilities.
Typical applications include wheat and grain silos, plants for concentrated and compound feed, and mills. In the food industry, modern silo production systems are essential for storing and loading flour, wheat and other raw materials. Their efficient, trouble-free operation is vital for maintaining a high product quality.
However, many of these systems still rely on conventional parallel wiring – with multiple on-site boxes, parallel lines and terminal points. This type of wiring is not only complex, but also expensive and prone to errors.
Conventional parallel wiring versus AS-Interface
With traditional parallel wiring, there are many connections, which means long installation time and complex maintenance. The installation complexity is particularly high in the case of pneumatic actuation of slides or flaps by solenoid valves.
In these applications, numerous transfer and withdrawal compartments are evenly distributed. With conventional wiring methods, installation is a complex and labour-intensive process. In contrast, with AS-i, all I/O points can be reached efficiently via the yellow flat cable.
Whether for detecting flap positions, signaling slide positions or actively opening or closing withdrawal compartments – AS-i easily solves all these challenges. No special knowledge about bus systems is required for installation and maintenance. All this makes AS-Interface a true ‘plug n play’ solution.
The great freedom in selecting the topology means that each I/O point in the system can be reached by the shortest route. The yellow AS-i flat cable replaces the once crammed cable trays, transferring energy as well as data to the connected sensors and actuators and to the controller.
For connection to higher-level systems such as PROFINET, Profibus DP, EtherNet/IP or EtherCat, AS-i masters are available.
Perfect team: AS-Interface and pneumatics
Pneumatics are often used in silo applications to actuate flaps or control valves. This is where the AS-i AirBox comes into play, a compact combination incorporating an AS-i I/O module and a solenoid valve which can be controlled via AS-i.
The installation process is straightforward: The yellow flat cable is placed in the lower part of the AirBox, the upper part is put on, and by actuating the slider, the housing is locked while contact with the AS-i cable is made at the same time. This quick mounting technology saves both time and costs.
The AirBox provides up to four inputs for valve position detection, e.g. using inductive sensors. The compressed air supply and the actuator are connected via standard pneumatic tubes. Practical option: A pneumatic test can be performed without voltage supply using the integrated manual actuation.
Costs savings with AS-iInterface
In pneumatics, significant cost savings can be achieved by preventing leaks. In such applications, the AirBox scores with its decentralized design: The valve sits directly on the actuator. This enables faster switching times and shorter pneumatic tubes, and thus, a pressure decrease in the system – a key factor in reducing energy costs and leakage losses. Thus, all the proven advantages of AS-i, ranging from low installation costs and reduced downtimes to easy maintenance and flexible expandability, can be fully leveraged in pneumatic applications as well.
Condition monitoring with AS-Interface
AS-Interface can also be used effectively in condition monitoring applications. For example, temperature, vibration and speed monitoring of drives can be seamlessly integrated into AS-Interface systems. Temperature and vibration diagnostics of drives can be implemented using a single analogue AS-Interface input module.
An example: For speed monitoring on drives, including signaling of overspeed or underspeed, a classic AS-i input module is used in combination with a speed monitor and an inductive sensor. The speed monitor is configured using the moneo configure software, and a limit value is defined, e.g. for under-speed. This state is then transmitted to the controller via the AS-i module. The drive speed can be read directly on the speed monitor’s 7-segment LED display.
AS-Interface is also suitable for use in hazardous areas as they exist in silos or flour processing plants. Thanks to ATEX approval for hazardous areas (zone 22, non-conductive dusts; II 3D), various AS-i components can be used to replace the complex parallel wiring.
Conclusion
AS-Interface is an efficient and cost-saving solution for a wide range of applications, from simple wiring to integration in hazardous areas. Thanks to its decentralised structure, fast installation and maintenance and flexible expansion capabilities, AS-Interface helps reduce installation complexity, energy costs and downtime. To sum up, AS-Interface provides a reliable, user-friendly and futureproof solution for automation systems.
