Digatron DT-31K2 User manual

OPERATING INSTRUCTIONS MODEL DT-31K2
KEYBOARD CONFIGURATION
POWER
ON
DIGATRON MODEL DT-31
TACH / EGT
MODE RECALL
MAXIMUM STORE
POWER OFFSET 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-31K2, be sure to set the operating
limits for each sensor. The instrument will not allow limits to
be set while the engine is running. This is to prevent
possible damage to your instrument.
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
kart’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 set the EGT limit. Set limits at levels
high enough for normal operation, but not so high that
engine damage can occur before you can respond to a
problem.
The tach limit requires the setting of two separate
parameters. The first is the maximum RPM for safe engine
operation. The second number is for tach calibration. In order
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.
The most frequently used numbers are:
.5 - for some single cylinder 4 cycle motors
1 - for single cylinder 2 cycle and some 4 cycle motors
2 - for 2 cylinder 2 cycle and 4 cylinder 4 cycle motors
If you are unsure of the exact tach calibration number for
your engine, experiment. If your calibration number is
currently set at 1 and the RPM displayed is double what it
should be, set the calibration number to 2. 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.
EXHAUST GAS TEMPERATURE
Exhaust gas temperature (EGT) is used primarily for adjusting
the air/fuel ratio. Because of its quick response, the effects of
carburetor adjustments are seen immediately. Fuel system
and carburetor problems can often be spotted quickly
enough to prevent engine damage.
Exhaust gas temperatures typically run between 1100°F and
1350°F. The EGT on a properly tuned engine will increase
rapidly as the throttle is opened and as the load on the
engine is increased. At full throttle and full load the EGT will
stabilize at a temperature dependent on the air/fuel ratio.
Both a “too lean” or a “too rich” condition will be indicated
by a lower than peak temperature. The “too lean” condition
can damage your engine. An increase in coolant temperature
or cylinder head temperature is usually an indication of this.
The best way to determine what temperature is normal for
your motor is to tune for good plug or piston color and then
observe the temperature at various throttle settings.
TACHOMETER
The tach displays RPM in thousands of RPM.
For example, if your display shows 9.50, your RPM is 9500
RPM.
MODE BUTTON
During operation, the MODE button is used to change from
the primary to the secondary function in the display. When
the instrument is first turned on, the primary function (tach)
is displayed. The secondary function (EHT) operates in the
background until the MODE button is pressed, or until it’s
limit is exceeded.
STORING DATA
The STORE button or the optional REMOTE STORE
switch can be pressed up to three different times to store the
current values of each function into memory. The display
and the optional WARNING INDICATOR LIGHT will flash
to indicate a successful store of information. After three sets
of numbers are stored, additional attempts to store
information will be ignored. In addition, the instrument
automatically stores a maximum value for each sensor during
the current recording period.

MEMORY RECALL
The MEMORY RECALL button is used to recall the
numbers stored in memory. To view the secondary function
(EGT) in the window, press the MODE button at any time.
To recall the first set of stored numbers, 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 set
of information. The middle decimal point in the window will
flash. A third press of MEMORY RECALL will bring up the
last set of numbers 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 values recorded for each input. Recording of these
values takes place automatically and requires no input from
the user. To display maximums, hold down the MAXIMUM
RECALL button. These values will be displayed until the
button is released.
Press the MODE button to display the secondary function
(EGT) in the window. Then press the MAXIMUM RECALL
button to display the maximum for this function.
DISPLAY OF OVER LIMIT/OVER RANGE
When conditions exceed the set limits, the display will flash.
The instrument automatically switches to this function if it is
not being displayed.
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.
ELECTRICAL INTERFERENCE
If the instrument encounters excessive electrical interference
it will display three vertical decimal points. This indicates
that the stored data could be invalid. It can also indicate an
incorrect instrument or sensor installation.
Severe electrical interference can cause the limits and
calibration number to reprogram themselves. If your
instrument is doing strange things, put it in the Set Limits
mode and check to see that the limits and calibration number
are still where you set them.
OPTIONS
There are three optional features that can be added to your
DT-31K2. To have any of these options added to your
instrument, send it to the address at the end of these
instructions.
WARNING INDICATOR LIGHT
The optional WARNING INDICATOR LIGHT flashes
constantly when any of the set limits are exceeded. It will
stop flashing when the conditions fall below the set limits.
The WARNING INDICATOR LIGHT will also flash once
when the STORE button or switch is pressed. Memory is
full if the switch is pressed and the WARNING INDICATOR
LIGHT does not flash.
BACKLIGHT
The BACKLIGHT lights the display for use at night. To turn
it on or off, press and hold the MODE and MAXIMUM
RECALL buttons simultaneously. The BACKLIGHT is an
optional feature; it will only work if installed.
REMOTE STORE
When mounted to your steering wheel, the REMOTE
STORE switch allows you to store three sets of numbers
while keeping your hands on your wheel.
BATTERY LIFE
An instrument not using a backlight will run for about 150
hours on a fresh set of AA alkaline batteries. With the
backlight on, the battery life will be approximately 50 hours.
Heavy duty batteries last about half as long as alkaline
batteries. The percentage of battery life remaining will
alternate in the lower window by holding down the
MAXIMUM RECALL button. The instrument will also
display “lo b” in the lower window to warn you of a low
battery condition. At this time the temperature functions will
become inaccurate, but the tach will display accurate
information for approximately one hour.
POWER OFF
The unit will turn itself off automatically after 10 minutes if no
tach input is detected or buttons are pressed. You can also
turn the instrument off manually by pressing the OFF and
the MODE buttons at the same time.Any stored data will be
lost when the power is turned off. View all stored information
before turning the instrument off.
REPAIRS
If you have any questions about the operation of your
instrument, please call. One of our technicians will be happy
to help you.
Your instrument is warranted to be free from factory defects
and electronic failure for one year from the date of purchase.
Physical damage during normal usage is not covered under
the warranty. Be sure to fill out and return your warranty card
for our records. If we do not have a card on file for your
instrument, you will be charged for repairs unless you can
provide us with proof of purchase date.
When returning an instrument for repair, enclose a note
indicating your return address, phone number and a detailed
description of the problem. Send your instrument and
sensors so that we can check the complete system.
Send repairs to: Digatron 8102 N. Freya St.
Spokane, WA 99217 www.digatron.cc
Phone: [phone] Fax: [phone]