Cisco Explorer 4700, Hardware Installation And Maintenance Manual

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Troubleshooting the Initial Hardware Configuration 4-7
Reading Network Processor Module LED Indicators
Table 4-1 Four Port Serial Network Processor Module LED Indicators
TC, RC, TD, and RD are on only when the associated line is changing state; if a line is stuck high
or low, the LED is off.
The names of the LEDs are given according to standard serial interface naming conventions. For
example, TD (transmit data) is always associated with the data that is driven by the DTE regardless
of whether the port on the four port serial module is a DTE or a DCE. This means that TD reflects
output data when the port is a DTE and input data when the port is a DCE. RD (receive data) is
controlled in a similar way. TC (transmit clock) and RC (receive clock) are always associated with
the clocks that are driven by the DCE: outputs for a DCE port and inputs for a DTE.
Dual Serial Network Processor Module LED Indicators
The dual serial network processor module has two LED cards. As viewed from the front
(see Figure 4-7), the left card is marked P-0 (for port 0), and the right card is marked P-1 (for port 1).
The lower serial port is port 0, and the upper serial port is port 1, as shown on the labels. There are
10 LEDs per port. System network processor modules can be configured for either DTE or DCE.
Figure 4-7 Serial Port Labeled V2
LED Labels and Colors Indication
LP (yellow) Loop
CN (green)
Connect (DSR, DTR, DCD, RTS, CTS
)
TD
(green)
Transmit data
TC
(green)
Transmit clock
RD
(green)
Receive data
RC
(green)
Receive clock
50-Pin
serial ports
LEDs
(4 green)
LEDs
(4 green)
LEDs
(1 yellow,
1 green)
Alignment
groove
Alignment
groove
H1484a
DO
SERIAL (V2)
PORT-1
PORT-0
TXC
DI
RXC
DCD
RS
TS1
TS2
LP
DCE
P-0 P-1