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Cisco 12016, Cisco 12416, and Cisco 12816 Router Installation and Configuration Guide
OL-11495-01
Chapter 2 Preparing for Installation
GRP Port Connection Guidelines
Caution
To maintain Class B EMI compliance, you must use shielded cables when
connecting to the auxiliary and console ports of original GRPs (part numbers
GRP= and GRP-B=). An updated version of the GRP-B= board (Rev. F0) does not
require shielded cables for Class B compliance.
GRP Auxiliary Port Signals
The GRP auxiliary port is a DB-25 DTE port for connecting a modem or other
DCE device to the router. The auxiliary port supports hardware flow control and
modem control.
Table 2-2
lists the signals used on the auxiliary port.
Table 2-2
GRP Auxiliary Port Signals
Pin
Signal
Direction
Description
1
GND
—
Shield ground
2
TxD
Output
Transmit data (to DCE)
3
RxD
Input
Receive data (from DCE)
4
RTS
Output
Request to send
(used for hardware flow control)
5
CTS
Input
Clear to send (used for hardware flow control)
6
DSR
Input
Data set ready
7
GND
—
Signal ground
8
DCD
Input
Carrier detect (used for modem control)
20
DTR
Output
Data terminal ready (used for modem control
only)
22
RING
Input
Ring