6K V1.02 03-16-91
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11.
LOGIC INPUTS
Your 6K controller has the ability to monitor "logical" devices at the repeater site. "Logical" devices
are sensors, switches, relay contacts and other devices that have an off/on output.
The controller has three logic inputs dedicated to this purpose. Also, the two receiver COR inputs
and the two CTCSS decoder inputs can serve as additional logic inputs.
Logic input #1 is pin 1 of J2. Logic input #2 is pin 2 of J2. Logic input #3 is pin 3 of J2.
Each logic input has a hardware circuit that is designed exactly like the RX1 COR input.
For Logic input #1, the transistor is Q1D, the voltage divider is made up of R11D and the resistor on
pin 3 of R12, and the pullup resistor is R17.
For Log input #2, the transistor is Q2C, the voltage divider is made up of R11E and the resistor on
pin 6 of R12, and the pullup resistor is R18.
For Logic input #3, the transistor is Q1B, the voltage divider is made up of R11G and the resistor on
pin 8 of R12 and the pullup resistor is R19.
You may wish to refer back to the "RECEIVER #1 COR" section of this manual for a discussion of
the hardware design of the input circuits.
To check your logic input interfaces, power up the sensor and the controller. Measure the voltage
at the appropriate pin of the controller's J2 connector. This voltage must swing above and below
the 2.1 V threshold as the sensor switches between its ON and OFF states.
The controller can detect both the low-to-high transition and the high-to-low transition of each logic
input. Therefore, there is no need to for sense-reversal dipswitches on the three dedicated logic
inputs.
Logic inputs are very handy for informing the controller (and the repeater's users) that some
external condition has changed. Examples include detection of AC power failure, high water, high
SWR, high temperature, intrusion, and so on.
The controller will execute macro commands upon sensing a change in state (transition) on its logic
inputs. Since the owner programs the macro commands, he can control the action that the
controller takes. This is a big improvement over controllers that take fixed action when an input is
tripped, such as sending a fixed CW message.
