Section 2
OPERATION
TIMEWISE 798A
49
AUTOMATIC
CALCULATED
TIME
ADJUSTMENTS
At the start of each leg of a rally, you will set the calculated time to your assigned out-time
and the main odometer to the official mileage. (See
Checkpoint Procedure
in
Section 3
for details.) If you follow all the rally instructions perfectly, the odometer and calculated
time will exactly match the rallymaster’s official figures throughout the leg. At least that is
what is supposed to happen.
Unfortunately, there is always some error in distance measurement due to wheel slippage,
lane changes, driving techniques, etc. Since distance measurement errors result in calculated
time errors, it will become necessary to correct both the odometer and calculated time.
Normally, correcting both the odometer and calculated time would be a three step affair. You
would have to correct the odometer, manually compute the required adjustment to the
calculated time, and then make the adjustment to the calculated time.
Fortunately, there is a faster, easier, and more precise method to automatically adjust the
calculated time while correcting the odometer. In fact, there are two methods. The first
method is to use the
Adjust ORM
function as discussed in
Adjusting the Odometer and
Calculated Time Together
. The second method is to use the
O d o & T i m e
function.
The two functions act very similar, with one exception. Distance adjustments entered using
the
Odo & Time
function are not considered an integral part of the current speed section. As
a result, if the Retro-CAST™ function is used after entering an
Odo & Time
adjustment, the
distance added or subtracted is not used during the Retro-CAST™ recalculation. To explain
further, here’s a complete description of the
Odo & Time
function, with additional
clarification on how it differs from the
Adjust ORM
function.
Odo & Time
Adjustments
With
Odo & Time
selected on the rotary switch, the “+ / –” toggle switches can be used to
adjust the main odometer. As the main odometer is changed, the calculated time is
automatically corrected to account for distance added to, or subtracted from, the main
odometer. The standard TSD formula is used to compute the calculated time correction:
CALCULATED TIME CORRECTION =
DISTANCE ADJUSTMENT
CALCULATION SPEED
While making an
O d o & T i m e
adjustment, both the
O D O M E T E R
and
CALCULATED
TIME
displays update instantly to show the results of your adjustment. (Note: the “+ / –”
.001
toggle switch is inactive if you are not viewing distance with “thousandths” resolution.
If you display thousandths only when split, you may adjust thousandths only when split.)
The adjustment made to the main odometer will be shown in the
AUXILIARY
display. This
“amount of adjustment” figure is shown regardless of the
TIME– –ODO
switch position. By
watching the
AUXILIARY
display, you can confirm the correction you enter. Upon de-
selecting
O d o & T i m e
, the
AUXILIARY
display returns to its normal usage and the “amount
of adjustment” reminder figure is reset. When you select
Odo & Time
again, the
AUXILIARY
display will always show 0.00 (or 0.000 if viewing thousandths of miles).
The
O d o & T i m e
function will work even when the 798A is split. As when adjusting any
split parameter, corrections to the split calculated time will be apparent as you enter the
distance adjustment, and will be included in the “live” values when you unsplit.
O d o & T i m e
adjustments are computed to a resolution of 0.0001 minute (0.01 second).
Thus, the adjustments are just as precise as if you had driven the distance.
