Verilink T1 ESF CSU (34-00309.B) Product Manual - Manual (Page 19)

Introduction 7
3
T
ESTING
Introduction
This chapter describes the diagnostic and test features of
Verilink’s T1 ESF CSU. The unit is controlled manually using
front panel DIP switches (the DIP switches are discussed on
page 5). The front panel indicators and side bantam jacks are
described below.
Indicators
The unit indicators convey major alarm conditions and looping
status.
POWER This green indicator lights when power is applied to the unit.
LOOPBACK This amber indicator lights under the following conditions: the
NET LOOP switch is set to Manual; the EQUIP LOOP is placed
in the Enabled position; or the unit receives an inband (or
out-of-band) loop code from the network.
NET LOS This red indicator lights if the internal alarm circuitry detects a
loss of signal condition for
≥
175 bit times or if it detects an
unframed error from the network. The indicator stays lit until the
unit detects
≥
4 pulses in 32 bit times.
EQ LOS This red indicator lights if the internal alarm circuitry detects a
loss of signal condition for
≥
175 bit times or if it detects an
unframed error from the DTE. The indicator stays lit until the
unit detects
≥
4 pulses in 32 bit times.
Loopbacks
Equipment
Position SW1-5 sets equipment loopback functions. When the
switch is set to Enabled, the unit is placed into an equipment
loopback where the DTE receives all the data it sends. The unit
sends an unframed all ones pattern to the network end. The unit
remains in equipment loopback until the switch is set to
Disabled.
Figure 3-1 Local Loopback
Equipment
T1 ESF CSU
Network
AIS