PairGain PG-Flex, Manual

Page: 67 / 168

Craft Port
59
Connecting to a Modem
A modem may also be connected to the craft maintenance port to allow remote access. In this
configuration, a null modem cable or adapter must be used between the line unit and the modem.
Figure 29 shows the pinouts for connecting to a modem using a null-modem cable cross-over.
Figure 29. Null-Modem Cable Pinouts
When configuring a modem, ensure that either the DIP switches or the software configuration is set
OFF for Carrier Detect (CD) override. This causes the modem to send the CD signal when it
connects with another modem and to drop CD when it disconnects. If set ON, the line unit
connection functions properly but does not log out properly when disconnected.
Set the modem as follows:
• 8 data bits
• 1 stop bit
• no parity
Using Data Carrier Detect (DCD) from the modem ensures that the line unit logs off if the carrier
signal disappears.
It is recommended that Data Terminal Ready (DTR) override be OFF. This allows a modem call
to terminate properly when the line unit drops DSR (which is null-modemed to DTR input on the
modem).