There is more information in Amendment A1 that I maybe should have quoted last time
"The Host shall be a typical compliant production sample" "PWBA intended to be class B shall not be tested in hosts which are class A" "The accompanying documentation shall include information regarding the host units in which the PWBA was tested and verified and information enabling the user to identify host units in which the PWBA will achieve compliance with the classifications (A or B)" Testing a product in one host allows the manufacturer of a PWBA to demonstrate compliance with the EMC Directive, and CE mark a product, by following the Standards Route to Compliance and testing against the relevant standard for their product, it cannot show that the product will pass in all hosts which unfortunately can, and does, make things difficult for people combining boards into systems. Unlike FCC part15 Computer Peripheral testing there are no "strict" guidelines in EN55022 as to how peripherals should be exercised whilst being tested, so it is indeed down to the manufacturer to be honest an exercise the PWBA fully during testing. I heard somewhere that the main reason for the Amendment A1 was to prevent PWBA manufacturers from testing in the proverbial Lead Lined Box, or testing it by simply powering it from a battery with no PC or bus activity in sight. Charlie

