| The AS-interface (AS-i) The actuator-sensor interface (AS-i) sets new technological standards in the design and automation of installations. This leads to economic advantages for the OEM and the user for project management, commissioning and maintenance of machines. In contrast to conventional fieldbuses AS-i has a finely granulated structure and can therefore be integrated even into proximity switches. AS-i considerably reduces wiring complexity since conventional parallel wiring of each sensor or actuator to the controller is no longer necessary. This saves the user a great number of terminals, splitter boxes, input / output cards and cable lines. Wide selection of connection options Via its field connections AS-i allows low-cost connection of conventional devices. Up to 248 binary sensors and 186 actuators can be connected per AS-i line. It is also possible to integrate sensors with bus capability into the system at any time. These sensors with integrated AS-interface supply more information to the controller without the need of additional wiring. Therefore this latest sensor generation is also referred to as intelligent sensors. Voltage supply and data via one cable Voltage supply and data communication of all sensors are normally performed via a (yellow) AS-i cable. For some modules actuators can also be supplied via this cable. If a higher output current or emergency stop switch-off is required, actuators are supplied via a second black flat cable with a separate 24 V auxiliary voltage. AS-i in the automation pyramid AS-interface has established itself at the lowest automation level, it is located below the fieldbuses. The strengths of AS-i are its simple structure, speed, quick wiring and price / performance ratio. It can be used as a feeder bus for higher bus systems, they in turn then ensure a non time critical transmission of the data over longer distances to the host controller. |