Tim Cicerchi, Product Manager
Joan Kassan, Technical Writer
Actuator Sensor Interface (AS-Interface) was introduced in the early 90’s as a distributed network to simplify interfacing sensors (inputs) and actuators (outputs). It was developed to reduce high installation costs and trouble-shooting difficulties associated with other networks. While AS-Interface may still be a simple network with low installation cost, its features make it an attractive option for a variety of applications.
For example, conveyor sections often vary in lengths in applications that transport 100-pound bags of cement, feed or fertilizer from a fill station to the palletizing station. During the build phase, industrial I/O modules can be mounted to the various conveyor sections, such as a bag accumulator, weigh station or dispenser. The keyed, trapezoidal-shaped cable is easy to install or remove, reducing re-engineering.
Termination is not required. As each conveyor section is added to the previous, the new modules are verified on the scanner. There is no need to wait for the entire machine to be laid out before programming can begin.
Typically, joining conveyor sections requires a break in the AS-Interface cable, which is done using simple flat cable splitters or flat to round converters. Reconnecting the conveyor sections is a snap.
In food and beverage applications, high-speed, continuous fill stations often require the use of many slip rings for distributed I/O. One ring is required for power, and a separate ring for every input and output on the rotating section.
Typically, 4 high-quality rings transmit over the noise-immune network into the filling section. At this point any number of I/O modules can transmit back to the host PLC or control system. The network’s cable is unshielded, with power and communication signals running on the same two conductors. Fewer wires mean fewer slip rings and ultimately, a lower cost machine. Flat cable technologies increase the level of protection to IP69K, perfect for wash down environments. Installations using stainless steel equipment and conduit often switch to round cable, which is very easy to pull through existing tubing.
Filed Under: Factory automation, Networks • connectivity • fieldbuses, Slip rings + rotary unions