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EXAMPLE: ADJUSTING VEHICLE SPEED FOR TIRE SIZE
Imagine that you changed tires from 185/60-14 to 195/55-14 and now the speedometer is incorrect because you haven’t
reprogrammed the ECM. The internet says that there would be a -1.3% difference and you want to compensate for that on the speed
gauge. This calculation looks like:
Constant Multiplier = 0.987
Adjusted Speed = Constant Multiplier * Vehicle Speed
To perform this calculation on the DashDAQ, try setting:
•
Input Signal:
Vehicle Speed from GenericOBD2
•
Multiplier Signal:
Constant Multiplier from Rescale Signal Calculator
•
Multiplier Sign:
1 (Positive)
•
Constant Multiplier:
0.987. This represents 100% minus 1.3%.
•
Offset Signal:
Constant Offset from Rescale Signal Calculator
•
Constant Offset:
0 to add/subtract nothing
The calculated value will be available when you assign signals to a gauge (section 0).
STATISTICS CALCULATOR (MIN / MAX / AVERAGE)
DashDAQ can calculate and display several statistics about a signal. Make sure that the “Statistics Calculator” was selected when
reflashing the firmware (section 0) and install the driver on an available port (section 0). This calculator can be installed several times;
once for each signal that you wish to average.
This driver has a few parameters:
•
Input Signal:
Signal for this calculation.
•
Time to Average (s):
Seconds of historical data to use in the calculation. For example, specify “1.5” to consider the past one-
and-one-half seconds of data.
•
Name:
Abbreviation to identify this signal. Displayed on the assign signals screen.
•
Precision:
Number of decimal digits to display.
After configuring, you may choose among several calculations on the assign signals screen:
•
Minimum:
Smallest value during “time to average”
•
Maximum:
Largest value during “time to average”
•
Smoothed:
Average value during “time to average”. Using this signal with a small (1-2 second) time to average is a great way to
filter signals that fluctuate wildly.
If you’ve assigned a statistic to a gauge but you’re not seeing values, double-check the Input Signal setting. Try assigning the input signal
to a gauge to verify that the DashDAQ is able to get a reading.
ANALOG INPUTS
DashDAQ has two analog inputs available on the accessory connector. They accept a 0-5v DC signal and are compatible with most
automotive sensors. These signals can be displayed on the gauge screens along with any other input. They can be rescaled from the 0-5v
scale into Fahrenheit, PSI, Air-Fuel ratios, or whatever the voltage represents. The analog inputs on DashDAQ have 24.7 kiloohm input
impedance and may not be accurate when connected to a device with high output impedance. For example, a narrowband O2 sensor
output cannot be connected directly to a DashDAQ because the output impedance of the sensor is in the megaohm range.
Summary of Contents for DashDAQ XL
Page 1: ...1 DashDAQ XL Instruction Manual ...
Page 14: ...14 MAIN MENU ...
Page 15: ...15 SETUP MENU MAP ...
Page 48: ...48 ...