The Keysight N4965A multi-channel BERT 12.5 Gb/s is a modular, multi-channel signal integrity test system ideal for characterizing multi-lane serial data channels. By adding remotely mountable heads, each of its 5 channels can be configured as either a generator, or error detector to form a bit error rate tester (BERT). Patterns available include various lengths of hardware generated PRBS, clock patterns, and DC logic 0 and logic 1. All heads can operate with differential or single ended signal connections. Output parameters in the generator heads and input parameters in the error detector heads can be programmed independently, or ganged together for convenience. Presets for common logic families simplify user set up.