Telenetics DSP9612RM - Manual (Page 22)

Installation
Page 22
SW2-5
− Soft Carrier (low-speed mode only)
SW2-5 ON = Disabled
OFF = Enabled
SW2-5 controls the soft carrier and is valid for low-speed mode only.
Setting this switch to OFF configures the modem to transmit a 900 Hz
soft carrier to the remote modem after RTS is turned off. Setting this
switch to ON prevents the modem from transmitting a soft carrier after
RTS is turned off.
SW2-6
− Production Test Only (high- & low-speed modes)
SW2-6 Must be OFF
SW2-6 must be in the OFF position for normal operation.
SW2-7
− 2-/4-Wire Operation (high- & low-speed modes)
SW2-7 ON = 2-Wire, Half-Duplex Mode
OFF = 4-Wire, Full-Duplex Mode
SW2-7 configures the modem for 4-wire full-duplex or 2-wire half-
duplex operation.
SW2-8
− Carrier Control (high- & low-speed modes)
SW2-8 ON = Constant
OFF = Switched
SW2-8 selects either constant or switched carrier. Constant carrier
allows DTEs, such as asynchronous dumb terminals or RTUs, to
operate with modems, without the input RTS signal. When constant
carrier mode is enabled (SW2-8 set to ON), the modem forces the
transmit carrier active and the RTS-CTS delay is minimum (<0.5 ms.).
You can use constant carrier in 4-wire, point-to-point or multi-point
applications (from master to slave modems).