98-16081a
Data
Port
LEDs
NET
DSU/CSU
3166
Port1
OK
Fail
Test
Sig
OOF
Alrm
EER
DTR
TXD
RXD
CTS
RTS
Select
In
Out
Net
Mon
SDCP Operation
3-6 3166-A2-GB20-10
November 1998

Table 3-3. Data Port (Port1) LEDs

Name Color Meaning
DTR Green Monitors the state of interchange circuit CD (CCITT 108/1, /2) –
Data Terminal Ready received from the synchronous data DTE.
ON:
DTR is being asserted by the synchronous data DTE.
OFF:
DTR is not being asserted.
TXD Green Monitors activity on interchange circuit BA (CCITT 103) –
Transmitted Data. This is the data sent from the synchronous
data DTE to the data port on the DSU/CSU.
ON:
Ones are being received from the synchronous data
DTE.
OFF:
Zeros are being received from the synchronous data
DTE.

CYCLING:

Both ones and zeros are being received from the
synchronous data DTE.
RXD Green Monitors activity on interchange circuit BB (CCITT 104) –
Received Data. This is data sent to the synchronous data DTE
from the data port on the DSU/CSU.
ON:
Ones are being sent to the synchronous data DTE.
OFF:
Zeros are being sent to the synchronous data DTE.

CYCLING:

Both ones and zeros are being sent to the
synchronous data DTE.
CTS Green Monitors the state of interchange circuit CB (CCITT 106) –
Clear-to-Send sent to the synchronous data DTE.
ON:
CTS is being asserted by the DSU/CSU.
OFF:
CTS is not being asserted.
RTS Green Monitors the state of interchange circuit CA (CCITT 105) –
Request-to-Send received from the synchronous data DTE.
ON:
RTS is being asserted by the synchronous data DTE.
OFF:
RTS is not being asserted.