Introduction to SMI

The automation of roller shutters and sun blinds in building automation is simplified with the SMI-Bus system (Standard Motor Interface). With SMI drives roller shutters can drive to precise positions and blind drives can drive to angular positions with an accuracy of a degree. The SMI drives can return actual positions, error messages and service information to the SMI master terminal.

Major European manufacturers have formed the SMI Standard Motor Interface e.V. and developed the digital interface. Drives are controlled by means of telegrams via this uniform interface. Using standard commands, functions can be implemented that are not so easy to realize with conventional drives. Examples are the precise movement to positions, the feedback of the current position and diagnosis. For the adjustment of louvers in shading systems, for example, angular resolutions of 2° can be achieved. Adjustment of the louvers in relation to the position of the sun is thus possible for constant light control.

For mains-voltage drives, the drive and controller are connected via a five-core cable for power supply and data transmission. Distances of up to 350 m between controller and drive are possible. The connecting cables are reverse-polarity protected to prevent damage to the drive in case of incorrect connection. Up to 16 drives can be connected in parallel and addressed individually. SMI drives are available for mains voltage (230 V_AC) and for low voltage (24 V_DC).

In order to ensure the compatibility of the SMI products with one another, all products that are to be marked with the SMI logo must be certified. A positive certification can be read on the SMI Group’s homepage (www.standard-motor-interface.com). Further information on the SMI-Bus and SMI drives can also be found there.