OPERATING INSTRUCTIONS MODEL DT-31SN
KEYBOARD CONFIGURATION
POWER
ON
DIGATRON MODEL DT-31
TACH
MODE
RECALL
MAXIMUM
STORE
POWER OFF
SET LIMITS
CLEAR
MEMORY
RECALL
POWER ON
When turned on, your instrument will begin a 10 second
display test. At the end of the test, your instrument’s serial
number will be displayed.
To bypass this test press the
MODE
button.
SETTING FUNCTION LIMITS
Before using your DT-31SN, be sure to set the operating limits
for the tach.
The instrument will not allow limits to be set
while the engine is running
. This is to prevent possible
damage to your instrument. Usually the instrument will turn on
without turning your engine on.
Limits allow the instrument to give you a visual warning if any
of the inputs exceed their limit.
Limits should be set at levels
that allow you to react to the visual warning before engine
damage occurs.
You will also need to set a calibration number
so the instrument can display the correct RPM.
To set the limits, the instrument must be turned on and the
sled’s engine turned off. Press and hold the
MAXIMUM
RECALL
and
MEMORY RECALL
buttons simultaneously
until the display flashes. This will put the instrument into the
Set Limits mode of operation, which is indicated by the display
flashing. To increase the limit, press the
MAXIMUM RECALL
button. To decrease the limit, press the
MEMORY RECALL
button. To increase or decrease the limit by a large amount,
press and hold either the
MAXIMUM RECALL
or the
MEMORY RECALL
button until the approximate limit value is
reached. When finished setting the tach limit, press the
MODE
button to go to the next value, which is the tach calibration
number.
The tach calibration number enables the instrument to display
the correct RPM for different engine types. The instrument
divides the tach input signal by the tach calibration number.
This number can be between .5 and 31. Select this number so
that it will provide the correct display for your application
using the
MAXIMUM RECALL
and
MEMORY RECALL
buttons.
Find the correct tach calibration number for your sled by
determining how many poles your lighting coil has and divide
this number by two. This is your tach calibration number.
The most frequently used numbers are:
2 cylinders - set at 2 or 4
3 cylinders - set at 3 or 6
4 cylinders - set at 4 or 6
If you are unsure of the exact tach calibration number for your
engine, experiment. If your calibration number is currently set at
2 and the RPM displayed is double what it should be, set the
calibration number to 4. Alternately, if the RPM displayed is
half of the correct value, decrease the calibration number to half
of the current number.
To save the current limits and exit the Set Limits mode, press
the
STORE
button or switch.
TACHOMETER
The tach displays RPM in thousands of RPM. For example, if
your display shows 9.50, your RPM is 9500 RPM.
STORING DATA
The
STORE
switch or the optional
REMOTE STORE
switch
can be pressed up to three different times to store the current
tach value. The display and the optional
WARNING
INDICATOR LIGHT
will flash to indicate a successful store of
information. After three numbers are stored, additional attempts
to store information will be ignored.
In addition, the instrument automatically stores a maximum tach
value during the current recording period.
MEMORY RECALL
The
MEMORY RECALL
button is used to recall the numbers
stored in memory. To recall the first stored number, press and
release the
MEMORY RECALL
button. The contents of the
first memory will be displayed and the left decimal point will
flash. Press
MEMORY RECALL
again to display the second
number. The middle decimal point will flash. A third press of
MEMORY RECALL
will bring up the last number and cause
the right decimal point to flash. Press
MEMORY RECALL
once more to return to normal display mode.
MAXIMUM RECALL
The
MAXIMUM RECALL
button is used to display the
maximum tach value recorded during the current recording
period. Recording of this value takes place automatically and
requires no input from the user. To display the maximum, hold
down the
MAXIMUM RECALL
button. This value will be
displayed until the button is released.
DISPLAY OF OVER LIMIT/OVER RANGE
When conditions exceed the set limit, the display will flash.
When conditions exceed the range of the instrument, three bars
will show at the top of the display. This condition can also be
caused by a bad or disconnected sensor.
