Chapter 1. Introduction
18
TSU 120 User Manual
61200.129L1-1
DTE loopback loops all data from the DTE back
towards the DTE. This loopback occurs just past the
interface circuit allowing a verification of the opera-
tion of the DTE to TSU 120. This loopback may be
initiated by using front panel or T-Watch commands.
The DTE (or external test equipment) must provide
anytest pattern to check the DTE interface. See Figure
1-10.
The TSU 120 also activates a port loopback when the DTE
loopback is asserted.
TSU 120
to DTE
T1
DTE
Loopback
Nx56/64
Interface
Nx56/64 to
network control
circuit
Network Interface
(NI)
Figure 1-10
DTE Interface Loopback
Port loopback loops that portion of the network
bandwidth programmed for a port back toward the
network. This loopback occurs within the port
electronics, but before the DTE interface. See Figure 1-
11. The port loopback also automatically activates the
DTE loopback looping the DTE data back on itself.
The port loopback is activated by command from the
front panel or from the T-Watch program. The port
loopback at the far end can be activated by command
from the front panel or from T-Watch.
Summary of Contents for TSU 120
Page 1: ...TSU 120 PART NUMBER 1200129L1 USER MANUAL 61200 129L1 1A July 1997...
Page 52: ...Chapter 2 Installation 38 TSU 120 User Manual 61200 129L1 1...
Page 132: ...Appendix C System Configuration Charts 118 TSU 120 User Manual 61200 129L1 1...
Page 138: ...Appendix D TSU 120 System Messages 124 TSU 120 User Manual 61200 129L1 1...