Telenetics DSP 9612 - Manual (Page 19)

Installation
Page 20
When the modem is configured for V.23 operation (SW2-1 ON), the
RTS-CTS delay is fixed at 33 ms.
SW2-6  FSK CD Delay (Bell 202 Mode Only)
SW2-6 ON = 23ms
OFF = 6ms
SW2-6 selects the FSK CD delay and is valid when Bell 202 mode is
active (SW2-1 OFF). Setting SW2-6 ON configures the modem to turn
on CD 23 milliseconds after it detects a valid carrier signal. Setting this
switch to OFF configures the modem to turn on CD 6 milliseconds
after it detects a valid carrier signal.
This switch setting is deactivated when the modem is configured for
V.23 mode (SW2-1 ON) and a delay of 18 milliseconds is used instead.
SW2-7  Remote Loopback
SW2-7 ON = Loopback enabled
OFF = Loopback disabled
During instances of channel noise, the modem may mistaken a received
preamble as a request to go into remote digital loopback. Setting SW2-
7 to OFF prevents the modem from participating in a remote digital
loopback with another modem. SW2-7 does not prevent the modem
from sending a remote digital loopback request to a remote modem.
SW2-8 − Reserved (Test Only)
SW2-8 Must be OFF
SW2-8 must be in the OFF position for normal operation.