In a test environment, logical test sites (of the test program) are associated with hardware test sites (of tester resources and sockets/probes). In general, accidental exchange of test sites can lead to yield loss, or worse, release of failing devices. It is therefore important to carefully ensure correct site assignment in environments with flexible hardware, like cable interfaces to rotary handlers with multi-station test programs. Regardless of the test methodology (index-parallel or multi-site) we must ensure that each software site talks to its dedicated test board. There should be mechanical keys installed on the handler to avoid the exchange of hardware units but there could also be electrical identification of those units to increase the level of security. This presentation will describe a method that ensures correct site identification from the software to the interface boards for a soft-docked rotary handler concept, either index-parallel or multi-site. We’ll discuss the advantages for the program, including managing per-site (or PCB specific) calibration values, hardware expansion and more.