Pin Assignments
D-5
3170-A2-GB20-20
December 1996
COM Port Interface
The COM port connects to a PC for front panel
emulation, to an ASCII terminal or printer for alarms, to a
network device (e.g., a router) for SNMP applications, to
the SNMP LAN Adapter for SNMP applications, or to
another E1 DSU/CSU’s AUX port for daisy chain
connectivity. (The SNMP LAN Adapter includes the
cable that is needed to attach it to the E1 DSU/CSU.)
The COM port connector is an 8-position keyed modular
connector (Table D-4). The data signals on this port are
referenced to a DTE interface.
The COM port-to-PC cable is shown in Figure D-3 and
the COM port-to-terminal/printer cable is shown in
Figure D-4.
NOTE
For daisy-chaining an AUX port
to a COM port, a customer
supplied, 8-pin-to-8-pin, straight-
through cable is required and
the appropriate configuration
options (Com Use and Aux Use)
must be set to Daisy. Whenever
the cable is connected or
disconnected, you should
change the Daisy selection to
ensure that the correct
parameters have been
negotiated for the link layer.
Table D-4
COM Port Connector
Signal
Direction
Pin Number
DCE Transmit Clock
From DSU/CSU
1
DCE Receive Data
From DSU/CSU
2
Signal Ground
—
3
DCE Transmit Data
To DSU/CSU
4
DCE Data Terminal Ready
To DSU/CSU
5
DCE Carrier Detect
From DSU/CSU
6
DCE Request-to-Send
To DSU/CSU
7
DCE Receive Clock
From DSU/CSU
8
