Operation
3-7
3360-A2-GB20-20
December 1996
Table 3-4
Data Port 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
Yellow
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 E1 NTU.
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
Yellow
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 E1 NTU.
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
Yellow
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 E1 NTU.
OFF :
CTS is not being asserted.
RTS
Yellow
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.
