ROC364 Instruction Manual
4-18 Communications
Cards
Rev
Jun/05
4.4.5 Dial-Up Modem Communications Card Wiring
The Dial-Up Modem Card interfaces to a PSTN line through the RJ11 jack with two wires. The
following signals, used only for monitoring or connecting to an analyzer to COM1 or COM2. These
signals are normally not active. To activate the signals, ground pin 7 (SHUTDOWN) to pin 5 using a
jumper. All unused signals can be left unterminated. The signals present at the RJ11 connector are:
RJ11
Terminal
Operating Mode
(2-Wire)
GRN Tip
RED Ring
Figure 4-15 shows the relationship between the Dial-up modem signals and pin numbers for the RJ11
and COMM port connectors.
Be careful to avoid shorting the +5 volt supply (pin 8 on the COMM port connector) to common
(pin 5) or to any ground when wiring to the COMM port. Grounding pin 8 causes the ROC to halt
operation and data may be lost once a restart is initiated.
Figure 4-15. Dial-Up Modem Wiring Schematic