Simple Electrical Transducer (SET) Standard

Trace Center Project Team:
Joseph M. Schauer, BSEE; David P. Kelso, MS; Gregg C. Vanderheiden, PhD


The Trace Center first became involved in the standardization area in order to deal with the problems encountered with user interfaces to communication, control, and computer access aids. At the time, there were approximately 65 specialized interfaces commercially available. Unfortunately, no two manufacturers, even by accident, chose the same connectors or connector pin assignments for their controls. As a result, clinicians were restricted to the use of only a small number of these interfaces, since the interfaces were not interchangeable across aids without rewiring either the interface or the aid.

The Trace Center initiated an effort and, working with manufacturers and researchers from North America, Europe and Japan, developed a Simple Electrical Transducer Interconnection Standard (SET standard). The original SET efforts led to an initial voluntary standard (SET Version 0.2), which was agreed to by a group of manufacturers. Since its introduction, about 80% to 90% of controls and devices addressed by the SET have conformed to most or all of the specifications. During 1987-88, a revision of the first standard was issued (SET Version 1.0), taking into account the suggestions and comments received from the field.

Figure 1.

[Figure 1 under the Simple Electrical Transducer (SET) shows the pin out descriptions for a 9 pin D male connector and a two 3.5 mm miniature phone plugs.

The 9 pin male connector pin numbers would be assigned to follow the SET standard as follows:

The 3.5 mm mono phone plug would have the tip act as switch A and the shell would act as the switch common. The 3.5 mm stereo phone plug would again have the tip act as switch A, the ring act as switch B, and the shell would again act as switch common.]


The SET Standard seeks to standardize: (1) the physical connections between user controls and electrical/electronic aids; (2) the electrical specifications of the interfaces between controls and aids; and (3) the categorization and labeling of controls and aids as to their electrical makeup. The standard has been circulated as a working paper among interested parties. The document is distributed through the Trace Center Reprint Service. The document lays out all aspects of the standard as simply as possible while still remaining accurate. Appendices provide a quick reference to pin assignments for connectors.


A final version of the SET is completed and in use by manufacturers in the augmentative communication field. The Trace Center distributes the standard through its Reprint Service, and answers questions from manufacturers regarding compliance with the standard.

The Trace Center will continue to support other organizations in their adoption of the SET standard. Future revisions or expansions of the standard may also be undertaken, but none are now planned.

Selected publications

Rodgers, B. L., Kelso, D. P., & Vanderheiden, G. C.(1984). Simple electrical transducer (SET) standard, proposal 0.2. Madison: University of Wisconsin, Trace Research and Development Center.

Schauer, J. M., Kelso, D. P., & Vanderheiden, G. C.(1988). Simple electrical transducer (SET) standard, version 1.0. Madison: University of Wisconsin, Trace Research and Development Center.