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controllere family. PC master The AS-i master card for the PC provides the full functionality of the PC (visualisation, process control, collection of data) in combination with the actuator-sensor-interface. The PC in its industrially compatible design and due to falling prices is increasingly used in automation technology as part of the machine control. Here the advantages of AS-i can be directly integrated into the system. The user can program in a high-level language by using the specific AS-i driver which ensures communication with the master card. Gateway to higher systems AS-i is designed as actuator-sensor-interface for binary participants. There- fore, couplers (so-called gateways) to higher-level bus systems (e.g. Profi- bus-DP) specially designed for larger data volumes are available. On the one hand, the gateway consists of an AS-i master which establishes the connec- tion to AS-i and on the other hand of a connection to the higher-level system to which the AS-i data are transferred. Concerning programming the AS-i master is treated like a participant of the higher-level bus. Examples of gateways are the Single-master system plc master AS-i allows exactly one master per system. This master polls all participants cyclically. Its location in the AS-i tree is unimportant because every partici- pant has its individual address. This address is stored non-volatilely in an EEPROM in every slave. The single-master system ensures constant defined cycle times which depend on the number of the participants and are 5 to 10 ms with the maximum capacity of the system.Depending on the application there are different options for connecting theactuator-sensor interface to the higher-level control system (host): Using the AS-i plc master card the controller CPU can directly access the AS-i periphery. The AS-i master and CPU normally communicate via the internal plc bus which is also used for the exchange of data by other inter- face connections, e.g. the input / output modules. This ensures a quick exchange of data and compatibility with existing plc programs. So the user can further use his existing software. Notes and explanations Master Master as the central part The AS-i operation, i.e. the communication with the slaves is continuously monitored and controlled in the master. These management functions are directly carried out at the hardware level of the master without a higher level of input being required from the user via programming. At the same time the binary information of the actuators / sensors is supplied to the higher- level control system (plc, PC, NC) via an interface. The data from the system’s inputs and outputs are presented in exactly the same way from the AS-i system as it would be from standard I/O modules thus programming in the control system remains unchanged allowing existing programs to be further used. Here the practical conception of AS-i can be clearly seen.
Generalinformation List of articles Controllers / Gateways, network extension Power supplies and earth fault monitors I/O modules for control cabinets I/O modules for field applications At the DeutscheShell AG in the plant Grasbrook over 2,000 valve actuators are networked via the AS-interface. Safety at Work AS-i sensors, pneumatic and actuator solutions Connection technology Accessories Technical information and customer service Visit our website: www.ifm-electronic.com

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