error ratio tester" or bit error rate test solution (BERTs) is electronic test equipment used to test the quality of signal transmission of single components or complete systems. The main building blocks of a BERT are: Pattern generator, which transmits a defined test pattern to the DUT or test system Error detector connected to the DUT or test system, to count the errors generated by the DUT or test system Clock signal generator to synchronize the pattern generator and the error detector Digital communication analyser is optional to display the transmitted or received signal Electrical-optical converter and optical-electrical converter for testing optical communication signals See also Burst error Error correction code Errored second Pseudo bit error ratio Viterbi Error Rate References External links QPSK BER for AWGN channel – online experiment Ratios Data transmission Network performance Error measures cs:BER