ETU-01(U) User Manual - CTC Union Technologies Co.,Ltd.

The ETU01 can select from one of five clocking mode settings.Chapter 1. IntroductionClock mode 0 (DCE 1):The ETU01 data channel operates as a DCE and provides both transmit andreceive clocks (recovered timing) to the data terminal equipment connected to theuser channel. The clocks are locked to the recovered E1 timing.DTEConnectedEquipt.TCClock Mode 0: RecoveryRCDCEDataPortE1transceiverTXRXE1Figure 1.1 Recovery timingClock mode 1 (DCE 2):The ETU01 data channel operates as a DCE and provides both transmit andreceive clocks (internal oscillator timing) to the data terminal equipment connected tothe user channel. The clocks are locked to the oscillator timing.DTEConnectedEquipt.TCRCClock Mode 1: InternalDCEDataPortOSCE1transceiverTXRXE1Figure 1.2 Internal TimingThe internal oscillator provides the clocking source for both the user data receivetiming out the RC and TC pins and the E1 transmit timing.12