scope:

This standard applies to interface systems used to interconnect both programmable and nonprogrammable electronic measuring apparatus with other apparatus and accessories necessary to assemble instrumentation systems. It applies to the interface of instrumentation systems, or portions of them, in which the

a) Data exchanged among the interconnected apparatus is digital (as distinct from analog)

b) Number of devices that may be interconnected by one contiguous bus does not exceed 15

c) Total transmission path lengths over the interconnecting cables does not exceed 20 m

d) Data rate among devices does not exceed 8 000 000 B/s

The basic functional specifications of this standard may be used in digital interface applications that require longer distances, more devices, increased noise immunity, or combinations of these. Different electrical and mechanical specifications may be required (for example, symmetrical circuit configurations, high threshold logic, special connectors, or cable configurations) for these extended applications.

This standard may also be applicable to other instrumentation system elements, such as processors, stimulus, display, or storage devices, and terminal units found useful in instrumentation systems. It applies generally to laboratory and production test environments that are both electrically quiet and restricted as to physical dimensions (distances between the system components).

This standard deals only with the interface characteristics of instrumentation systems to the exclusion of design specifications' consideration of radio-interface regulations, performance requirements, and safety requirements of apparatus.

NOTE-For the latter two items, reference is made to IEC 61010-1: 2001, and IEC 60359:2001.¹

Throughout this standard, and insofar as further distinction is not necessary, the term "system" denotes the bit-parallel byte-serial interface system that, in general, includes all circuits, cables, connections, message repertoire, and control protocol to effect unambiguous data transfer between devices; and the term "device" or "apparatus" denotes any programmable measurement device or other product connected to the interface system that communicates information via, and conforms to, the interface system definition.

A primary focus of this standard is to set forth an interface system to interconnect self-contained apparatus to other apparatus by external means. This same standard may be applied to interconnecting the internal subsections within a self-contained equipment.

¹For information on references, see Clause 2.