Monarch Instrument TACH-4AR - Manual (Page 6)

POWER/LOCK When the instrument is “locked on”, the POWER
button will turn the unit off. When not “locked
on” the POWER button must be depressed and
held to take a reading. Each time POWER is
pressed, the previous Minimum and Maximum
value is cleared, and the optics are turned on to
take the next reading. When the POWER button is
released, the Tachometer holds the last reading for
60 seconds, then automatically shuts off.
NOTE: None of the following buttons will function when the POWER
button is being held.
RECALL/STORE Used to display the stored Maximum or Minimum
value. When pressed, the unit will display “MAX”
or “MIN”, then the value. The reading alternates
between the Maximum and Minimum values each
time this button is pressed. The value is displayed
for 2 seconds, then the display returns to the last
measurement.
RESET/LOCK Resets the minimum, maximum, and last measure
ment to Zero.
LEFT ARROW (") Turns the LCD back light on for 60 seconds
(assuming the backlight is not already on)
SCALE MODE
Operation is the same as for the RPM mode, except that the measurement
is scaled. In the RPM mode, the input frequency is automatically
multiplied by 60 to display in Revolutions Per Minute. In the scale mode,
the input frequency (pulses per second) is multiplied by a user defined
scale factor. As an example: for two pulses per revolution and a desired
readout in RPM, the Scale Factor is 30. (60 / pulses per rev = Scale
Factor) The scale factor can range from 0.0001 to 99999. This allows the
user to display data in real engineering units.
REMOTE SENSORS (TACH-4AR ONLY)
The remote sensors plug into the stereo phone socket on the end panel
of the unit . The unit automatically detects the remote sensor at ‘turn on’
time and powers the remote sensor on as needed. If you plug a remote
sensor in while in the middle of a measuring operation, the unit will not
recognize the remote sensor. It is then necessary to turn the TACH-4A
off, then on again. Remember to press and hold the POWER button
or ‘lock-on’ the unit to take a reading with a remote sensor.
It is often useful to turn the TACH-4A on in the “LOCK” mode when using
remote sensors. Plug the sensor in, then press and hold the RESET/
LOCK button and press the POWER button to turn the unit on and
permanently power the sensor. Refer to individual modes for further
instruction.
PO, PULSE OUTPUT (OPTIONAL)
The Pulse Output is an option for both the TACH-4A and TACH-4AR. This
option includes a 2.5mm phone socket installed on the lens panel of the
Tachometer and a six foot cable with mating 2.5mm phone plug to male
BNC connector enabling the user to interface with a standard BNC cable.
The Pulse Output is a 0 to 5 Volt TTL compatible output. Every input
pulse gives an output pulse. Normally, the Tachometer is used with one
pulse per revolution, therefore the output would be one pulse per revolution.
If the Tachometer is used with more than one pulse per revolution, the
output will echo the input, thus providing more than one pulse per
revolution.