Claiming to dramatically reduce design time and cost of adding phase synchronization to systems such timing signal generators, Stratum 3 and 4E simplified control timing modules act as complete integrated clock subsystems in one compact unit. And full external control inputs allow for selection and monitoring of any of four operating states: holdover, external clock #1 and #2, and free run. The timing modules come in T1, E1 and 16.384- and 19.44-MHz frequencies.