DSP9612RM USER’S GUIDE
0049-0519-000
Page 17
REV.D
SW3-7
−
2-/4-Wire Operation
SW3-7
ON = 2-Wire, Half-Duplex Mode
OFF = 4-Wire, Full-Duplex Mode
SW3-7 configures the modem for 4-wire full-duplex or 2-wire half-duplex operation.
SW3-8
−
Carrier Control
SW3-8
ON = Constant
OFF = Switched
SW3-8 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 (SW3-8 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).
In switched-carrier mode (SW3-8 set to OFF), the RTS/CTS delay is active.
SW3-9
−
RX Termination
SW3-9
ON = Enable Rx Termination
OFF = Disable Rx Termination
SW3-9 selects whether RX termination is enabled for a modem. If you set this switch
ON, the receiver is terminated with 600
Ω
. If you set this switch OFF, the receiver is not
terminated.
SW3-10
−
Grounding Option
SW3-10
ON = Signal Ground and Earth Ground are Connected
OFF = Signal Ground and Earth Ground are Separated
