MT56DSU2 Owner’s Manual
82017502
19
Chapter 4 - Troubleshooting
4.1 Introduction
All of the indicators used in normal operation of the MultiDSU56K are on the front panel. Each
front panel LED is labeled, as explained below. The LEDs provide status and maintenance
information on the MultiDSU56K, as well as the attached network and line. There are no front
panel switches on the MultiDSU56K; refer to Chapter 2 of this manual for option configuration DIP
switch settings.
4.2 LED Indicators
The front panel contains twelve LEDs each with a two- or three-letter overlay, and a one-word
legend below the LED describing its meaning. During normal operation the LEDs light (flash or
continuously lit) to indicate a defined condition. During test mode, the LEDs light during Test
Pattern test execution (refer to the Test Pattern section later in this chapter).
The front panel LEDs are shown below.
NS
DOS
RTS
CTS
Send
Rcv
Carrier
56K
19.2K
9600
4800
Clear Request NoSgnl Outage
Test
MultiDSU56K
RD
CD
SD
96
48
19.2
56
TM
Multi-Rate DSU/CSU
Figure 4-1. MultiDSU56K Front Panel
4.2.1 SD Indicator
The SD (Transmit) LED lights to indicate the DTE is sending data (0 or a space) across the DTE
connector.
The SD LED should appear to flash during normal data transmission.
4.2.2 RD Indicator
The RD (Receive) LED lights when the MultiDSU56K receives data (a 0 or a space) from the
network.
The RD LED should appear to flash during normal data reception.
4.2.3 CD Indicator
The CD (Carrier Detect) LED lights when the MultiDSU56K has received the data carrier from the
network. This indicator will go off when the MultiDSU56K is receiving the idle code or no signal at
all. If RTS is off on the remote DSU, the remote DSU sends an idle code to the local DSU.
4.2.4 56K Indicator
The 56K LED lights when the “Data Rate” selection is set at 56000 bps. This indicator will be off
for all other data rates. Refer to Chapter 2 for switch settings.
4.2.5 19.2 Indicator
The 19.2 LED lights when the “Data Rate” selection is set at 19200 bps. This indicator will be off
for all other data rates. Refer to Chapter 2 for switch settings.
