Microwave Data Systems MDS 4310, Установка, эксплуатация и техническое обслуживание на месте

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MDS 05-2415A01, Rev. A INSTALLATION 2-9
PIN 11: Receiver Filtered Audio Output—Line Level
(Continued)
If the distance to the modem or RTU is greater than five feet (1.52 meters), use a
twisted pair of conductors to make the connection. Connect one end of the pair to
the audio input terminals of the modem or RTU and the other end to pins 11 and 7
of the
INTERFACE
connector.
PIN 12: Radio Disable
A ground on this point will totally disable the radio, including transmit, receive,
modem and diagnostic functions. The pin controls the +8 Vdc used by all
transceiver circuits. The
I N
LED is lit when Pin 12 of the
INTERFACE
connector is
grounded. This input can be used to reduce power consumption during periods of
non-use.
PIN 13: Transmitted Audio Output
with internal modem
This is the audio output of the modulator IC in the modem and is provided for test
purposes.
PIN 14: PTT (Push-To-Talk )
This is one of two transmitter keying (PTT) inputs. The PTT input is normally at
ground. When this pin is pulled up to greater than 4 volts, the transmitter is keyed;
when the pin is at less than one volt (“open” circuit), the transmitter is off and the
receiver is active. See pin 16 description.
PIN 15: TC—Transmit Clock
This pin is used only on applications requiring a synchronous interface. This pin
provides a signal to clock transmit data bits out of the terminal connected to the
radio. The Transmit Clock signal is compatible only with RS-232 interfaces.
PIN 16: Push-To-Talk (PTT)
This is an active-low PTT input, pin 16, it acts in the opposite way from pin 14; it
is normally at 5 Vdc. When it is pulled down to less than one volt, the transmitter
is keyed; when it is greater than 3 volts (“open” circuit), the transmitter is off.
PIN 17: RC—Receive Clock
This pin is used only on applications requiring a synchronous interface. This pin
provides a clock signal to clock receive data bits from the radio to the terminal
connected to the radio. The Receive Clock signal is compatible only with RS-232
interfaces.
PIN 18: +13 Vdc Unregulated Source
This pin provides a convenient source of unregulated 13 Vdc at 0.5 A for
powering external low current equipment. This connection provides the primary
power to the radio with no regulation. Excessive drain on this connection will
blow fuse, F1, on the transceiver board.