Control Receiver Cor - S-COM 7K Manual

Control Receiver COR

A control receiver is a wise addition to your repeater system, as it allows you to
control the repeater on a frequency other than the repeater's input. Users of
the repeater will not notice any change in operation while the control channel is
occupied, except that the repeater will not accept any of their DTMF
commands. Additionally, any Command Response Messages will be sent over
the repeater transmitter that are caused by commands received from the
control channel (unless these response messages have been turned OFF by
command). When the control channel is released, all operations return to
normal.
If you want to implement a control channel function, you must supply both the
following from your control receiver: A COR signal and audio.
The control receiver COR signal can be either low active or high active. This
signal should be connected to Pin #4 of J2 (the female DB25S connector), the
RX3 COR Input.
No software currently exists to support the RX3 PL Input; therefore, if you wish
to use a CTCSS decoder on the control channel, you must connect the output
of the decoder to the RX3 COR Input.
Better yet, externally "and" together the COR and CTCSS decode signals, and
feed the result into the RX3 COR input. Unless the correct CTCSS tone is
recognized by the decoder, the controller will ignore the control receiver. The
control receiver COR input to the controller is similar to the repeater receiver
COR input. The voltage divider is made up of one resistor from network R10
and one resistor from network R11. The pullup resistor is R14. (You may refer
to the Repeater Receiver COR section on page C-3 for a discussion of the
hardware design of the input circuit.)
To check your installation:
• Measure the voltage at Pin #4 of J2 with the control receiver and controller
powered up.
• The voltage should swing above and below the 2.1V threshold as an
incoming carrier is applied and removed.
You must also determine the sense of your control receiver COR output signal.
• Does the output go low or high when an incoming carrier is detected and
returns high when the carrier is removed? If so, place DIP Switch #3 in the
ON (closed) position.
• If, however, the output goes high when the carrier is detected and returns
low when the carrier is removed, place DIP Switch #3 in the OFF (open)
position.
Note: If you do not use a control receiver, be sure DIP Switch #3 is in the ON
(closed) position. This configures the controller for a low-active COR signal.
The pullup resistor on the input will hold the input high, thus releasing the
DTMF decoder from the control channel.
Installation
C-9