Red Lion LEGEND - Manual (Page 44)

SIGNAL WIRING
INPUTS A & B
Input A and Input B have the same input circuitry. Input A and Input B each
have separate DIP switches for setting the type of signal input. A Magnetic
Pickup or Logic Input signal can be sent to either input. When a MAGNETIC
PICKUP is used, the Sink/Source DIP switch, for the appropriate input, must be
in the “SRC” position or the unit will not count. The HI/LO FRQ DIP switch will
effect the maximum input frequency at that input.
The Input schematic shows the details of Input A and Input B circuitry and share
the same common. Each input has three DIP switches associated with its input.
The functions of these switches are as follows:
INPUT A
SW1 - MAG: Sets input for a Magnetic Pickup signal.
Sensitivity: 200 mV peak; hysteresis: 100 mV
LOGIC: Sets input for a Logic signal.
Input trigger levels: V
IL
= 1.5 V max; V
IH
= 3.75 V max.
Note: SW2 & SW5 must be in the “SRC” position for a Magnetic Pickup signal.
SW2 - SNK: Provides a 7.8 K internal pull-up resistor for sensors with current
sinking outputs.
SRC: Provides a 3.9 K internal pull-down resistor for sensors with
current sourcing outputs.
SW3 - HI FRQ: Removes damping capacitor and allows operation up to the
max. frequency.
LO FRQ: Connects damping capacitor for switch contact debounce.
Limits count speed to 50 cps max. Min. count pulse ON or OFF
time - 10 msec.
Note: The HI/LO FRQ selection switch must be set on “LO FRQ” when switch
contacts are used to generate count input signals. The “LO FRQ” mode also
provides very high immunity against electrical noise pickup, it is
recommended that this mode also be used, whenever possible, with electronic
sensor outputs. The “LO FRQ” mode can be used with any type of sensor
output, provided count pulse widths never decrease below 10 msec, and the
count rate frequency does not exceed 50 cps.
INPUT B
SW4 - Same as SW1
SW5 - Same as SW2
SW6 - Same as SW3
Note: A Magnetic Pickup type sensor should not be used unless a large enough
signal is provided at all speeds of operation.
-42-