A Trigger/Timing Logic Unit for ILC Test-beams

Detector development for the International Linear Collider (ILC) is likely to involve initial beam-tests with a triggered configuration, moving to beam-tests in a triggerless or self-triggered mode. A Trigger/Timing Logic Unit (TLU) is described which allows triggered operation, with option of smooth transition to trigger-less, data-driven mode. The unit has already been sucessfully used for a number of beam-tests.