Actuator Sensor Interface for Kinetrol Vane Actuators

Kinetrol AS Interface

Devices conforming to the AS interface (Actuator Sensor interface) set of open specifications are used to make up control systems based on a two-wire communication cable known as a bus. Up to 31 actuators and sensors (“slaves”) can be connected to the AS interface bus, and can be controlled or monitored by means of a digital signal sent via the bus to and from a “master” device (which can be a computer or a PLC).

The slave devices will always function in response to commands sent by the master device, either to actuate, or to return a message reporting the value of a sensed variable, or both. The AS interface 2.1 specification allows 31 slave devices to be powered by a DC voltage fed into the same two-cable wire used as the communication bus, with allowed power consumption adequate to drive the slave plus a standard pneumatic solenoid valve. Under extended addressing, a maximum of 62 slave devices can be connected via one bus, but specified limits on device capacitance make this applicable only to systems with limited numbers of solenoid valves, or with a special scheme to get round the limit (see overleaf).

An AS interface bus can be used as the final field link in a more complex hierarchy of devices making up a large plant-wide control system. Actuators and sensors must often be installed in unprotected environments where conditions can be demanding; the AS interface bus is ideal for using as the link between these field devices and the “indoor” equipment making up the upper part of the control system.

AS interface is well suited to on/off control and monitoring, and is a good choice when a simple economical, reliable and robust solution is required to control and monitor a series of actuators and sensors in a process control or machine application. Kinetrol’s AS interface Universal Limit Switch Box is designed to meet all of these requirements.


The Kinetrol AS interface circuit board is fitted inside a standard actuator-mounted Kinetrol Universal Limit Switch Box (2 or 4 entry), so that the actuator (and up to 30 others like it) can be controlled, monitored and powered directly via a single two-conductor digital communication cable (or bus), using the open AS interface 2.1 standard. All the advantages of the limit switch box (all-metal construction, corrosion resistant, up to IP67 sealing, easy connection, easy setting of limit switch strikers etc - see KF487 literature) combined with the highly specified AS interface circuit to give unique levels of practicality, genuine industrial quality, and use-anywhere adaptability.

See thr full feature set and documentation below.

Kinetrol ASI Communications Interface from Kinetrol USA