CTC Union ETU-01A, Installation And Operation Manual

Page: 105 / 144

Chapter 5. Loop Back and BERT Testing
99
November 2001
Data Port local digital loop back.
Data Port local digital loop back is performed by connecting the
local data channel receive data (RD) to the data channel transmit
input (TD), as shown in Figure 5-7. The test signal is then provided
by the remote user DTE.
Figure 5-7. Data Port local digital loop back
User
DTE
Data
Port
E1
E1 LINE
LOCAL ETU-01A
DSU
CSU