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Chapter 7 - DIP-Switch Settings
Switches #13 and #14
Speed Switches
(Synchronous Mode/Leased Line)
DIP-Switches #13 and #14 are used to set the modem’s data transmission rate. Switches #13 and
#14 are used in combination, typically in leased-line and call origination applications.
Note: The modem baud rate command (
$MBn
) overrides the setting of these speed selection
switches (DIP switches #13 and #14).
28800 bps Operation = Switch #13 UP and Switch #14 UP
19200 bps Operation = Switch #13 DN and Switch #14 UP
14400 bps Operation = Switch #13 UP and Switch #14 DN
9600 bps Operation = Switch #13 DN and Switch #14 DN
Factory Default Setting = Switch #13 UP and Switch #14 UP
Switch #15
Carrier Detect/DSR Forcing -- "DSR"
(Asynchronous/Synchronous Mode/Dial-Up/Leased Line)
Some terminals react in unusual ways to the toggling of the Carrier Detect (CD - RS-232C/V.24 pin
6) signals. The most common symptom is that the modem does not respond to commands, or does
not echo characters. In these cases, it is advisable to force these two signals On in order for the
terminal to communicate properly with the modem in Command mode. This is done by setting DIP-
Switch #15 DOWN. With DIP-Switch #15 in the UP position, both CD and DSR will be either on or off,
depending on the On-Line status.
CD and DSR normal = Switch #15 UP
CD and DSR forced On = Switch #15 DOWN
Factory Default Setting = UP
Switch #16
(Reserved for Future Use)
7.3 Speaker Volume Control
You can adjust the volume of the modem’s phone-line monitor speaker with a volume control knob,
located on the back of the modem next to the RS-232C connector (see Figure 9-1 for location). Turn
the knob clockwise to increase the modem's volume and counterclockwise to decrease speaker
volume.