OPERATION
Section 2
36
TIMEWISE 798A
Automatic
Warning
of an
Odometer
Transducer
Failure
If you are operating with two odometer transducers, a unique Intelli-Sense™ system in the
798A can determine if one of those installations is failing.
In order for the Intelli-Sense™ warning system to function correctly, there are a few
requirements. First, you must start with two functioning transducers. Secondly, the active
factors for each transducer must have been set to approximately correct values. And lastly,
both transducers must operate correctly for a short distance (about 0.03 mile). (The 798A
uses these conditions to initially correlate the distance measured by both transducers.)
If the 798A detects a problem with an odometer input, the
CLOCK
and
CALCULATED
TIME
displays will show the warning “
I n P u t 1
SU S P E Ct
”, or “
I n P u t 2
SU S P E Ct
”,
indicating that a particular transducer installation appears to have failed.
The failure warning can be dismissed by activating
SHIFT
, adjusting the factor, changing
odometer inputs, or (as of version 5.009 firmware) by turning the rotary switch. It is up to
you to determine if there really is a failure and, if necessary, change the input transducer.
After acknowledging a suspected failure by operating the
SHIFT
switch or adjusting the
factor, the warning system will not be reactivated until you change odometer inputs. If you
do change inputs, but do not correct the problem, the warning will likely re-appear.
The failure detection system is designed to allow as much leeway as is reasonable when
correlating the way two different transducer installations sense distance, without causing
unnecessary warnings during hard braking, heavy acceleration, or sharp cornering. The
intent of the warning system is primarily to give rapid warning should a magnet be
dislodged from a wheel, or when a transducer fails completely.
The transducer failure warning system is not intended to warn you of random missed pulses.
You can, however, often use the driver’s speedometer readout for that purpose. If a pulse is
skipped while the 798A is measuring your speed, the speedometer value will momentarily
decrease by 5% to 10%. (The 798A measures your speed approximately twice per second. If
a pulse is skipped between speed measurements, the missing pulse will not be evident.)
Automatic
Factor
Calculation
Instead of manually calculating new odometer factors, you can let the 798A compute new
factors for you. The
Odo Check
and
Compute Factor
functions are used for this purpose.
Whenever
Odo Check
is selected on the rotary switch, the
AUXILIARY
display shows an
“official odometer check distance” — a value you set in the 798A. (The odometer check
distance is automatically displayed regardless of the
TIME– –ODO
switch position.) At the
same time, the active factor is shown in the
CL O CK
display. With
Odo Check
selected on
the rotary switch, the “+ / –”switches will adjust the official odometer check distance.
To correctly carry out the automatic factor calculation, here’s what you have to do:
At the start of the odometer check, reset the main odometer (to 0.00000000 mile). Then
begin driving the route. Prior to finishing the odometer check, select
Odo Check
and enter
the official odometer check distance into the
AUXILIARY
display. This value can range from
0.001 to 99.999. (You can enter the odometer check distance at anytime. The value is saved
in memory when the rotary switch is rotated away from the
Odo Check
position.)
As you approach the end of the odometer check route, select
Odo Check
on the rotary
switch. Then depress (and hold) the
SHIFT
switch. This arms the
Compute Factor
function. At the exact point on the course that is the end of the odometer check, actuate any
