What is a URN and why is it needed?
The unique registration number is a 64-bit unique identifier contained in the memory devices, or nodes, in which IEEE 1451.4 TEDS data is stored. Because multiple nodes may be arrayed in a multi-drop network format, to allow memory capacity to be increased, or other functions to be added, the URN allows a number of nodes to be individually accessed by the system. (see IEEE Std 1451.4.2004 subclause 5.4, figure 2) For details on the use of the URN in node devices, click here. Do not confuse the URN with manufacturer ID and basic TEDS, as they are two separate and distinct entities. IEEE 1451.4 transducer manufacturers using commercially available nodes obtain a URN automatically in each node they purchase. Manufacturers wishing to emulate the IEEE 1451.4 node function with an ASIC or micro-controller, for example, must purchase a URN for each node function produced. For this purpose, the IEEE Registration Authority issues blocks of 4096 URN codes. If you are producing nodes for use with
