4
Firmware Disabled. CS0-Least significant bit of the channel select lines. Active
high 5 volt TTL/CMOS level. Internal 10 k
pull-up to +5 volts.
Channel
CS1
CS0
1
0
0
2
0
1
3
1
0
4
1
1
0 = Logic low
1 = Logic high
Note: Due to the internal pull-up resistors, the unit defaults to channel 8 if the
channel pins are left open (unconnected).
Channel 4 would be the nominal
channel when the Ritron programmer is connected.
5
RSSI-
This is an analog output whose amplitude is proportional to the signal
strength of the received signal. The voltage at this pin varies from about 1.6 VDC
for a -130 dBm signal to about 4 VDC for signals at or above -60 dBm.
6
RAW SUPPLY- Supply voltage input. +10VDC to +16VDC.
7
DISC OUT- Buffered Discriminator Audio with DC Bias.
8
RD- Connect via RITRON DTXP-PCPK PC Programming Kit to computer for
programming the unit.
9
TD-Connect via RITRON DTXP-PCPK PC Programming Kit to computer for
programming the unit.
10
CTS-Clear-To-Send output from the unit which indicates that the unit is
transmitting a carrier at the correct frequency and power level and is ready to
accept an input signal to be transmitted. This output would normally become
asserted in response to a PTT RTS (see pin 14 description below) activation.
The polarity of this output can be programmed. The output is active low 5 volt
logic with an internal 10 k ohm pull-up to 5 volts. It can source up to 10 mA when
low.
11
Firmware Disabled. CS1-Most significant bit of the channel select lines.
12
TEST/PTT- Push to Talk/Request to Send. This input commands the unit to
transmit. Input levels are TTL/CMOS; polarity may be programmed. Internal 10
k
pull-up to +5 volts.
13
CD-Carrier detect output. This output becomes asserted when a signal strong
enough to exceed the programmed squelch threshold is present. This output is
not affected by the RX MON input. The polarity can be programmed. The output
is active low 5 volt logic with an internal 10 k
pull-up to +5 volts. It can source
up to 10 mA when low.
14
RTS-
This RS-232 input pin is asserted by the host computer or device to
indicate that it has data to be transmitted by the modem. If the modem is able to
accept the data, the CTS pin will be asserted in response.
15
GND-System ground. All signals and voltages are referenced to this input. The
negative side of the power supply should connect here.
