DashDAQ Series II XL -- FAQ

1. How do I show the Air Fuel Ratio as a Lambda value on the DashDAQ?

Follow the directions for setting up the Rescale Signal Calculator on the DashDAQ Series II.  These instructions contain the steps and values needed to convert the Air Fuel Ratio from the Zt-2 into a Lambda value.

If you have a pressure or temperature sensor connect it to the User2 input on the Zt-2.  This input can be configured to read the pressure or temperature sensor directly with no conversions necessary.  For temperature sensors follow the temperature sensor installation instructions.  For pressure sensors the installation is the same as a MAP sensor with the green signal wire attaching to the User2 input instead of the boost input. Using the Zeitronix Data Logger software configure the User2 input for the particular sensor you are using.

To view the User2 data on the DashDAQ display choose the Zt-2 device "Analog 2" signal from the Zt-2 device signal listing.  If the DashDAQ display does not list "Analog 2" as a Zt-2 device signal please contact us for information on updating the DashDAQ firmware to support this feature.

If you need to convert the User input voltage to a pressure follow the directions for setting up the Rescale Signal Calculator on the DashDAQ Series II.  Specific values are given for all Zeitronix pressure sensors.

Methods and values needed for reading a temperature sensor on the User input will be added soon.  Please contact sales@zeitronix.com if you need information on setting up a second temperature sensor on this input.

3. How do I correct the RPM reading from the Zt-2 Wideband System on the DashDAQ?

If the Zeitronix RPM reading is too high or too low please set the "Number of engine cylinders" parameter by following these directions...

1. From the Main Menu press the "Parameters"
2. Choose the Zeitronix device at the top.
3. Choose the "Number of engine cylinders" value then click on the "Change" button.
4. Enter the number of engine cylinders your vehicle has.  Save it. 

The default value for this parameter is 4.  Due to differences in ignition system you may need to adjust this value by taking half or doubling the actual number of cylinders in the vehicle.  If the RPM signal is attached to a crank shaft sensor or counter you may need to enter the number of steps this counter has per one revolution (which may be a large number).

4. How do I view logs from the DashDAQ using the Zeitronix Data Logger software on a PC?

1. From the Main Menu press the "Data Logging" button.
2. Press the "Log File Type" button.
3. Choose the "Zeitronix ZDL 3.0" value then click on the "OK" button.

The log files will be created with the extension "zdl".  These files can be viewed directly by any 3.0 or higher versions of the Zeitronix Data Logger software.

• Air Fuel Ratio to Lambda
• Voltage to Pressure
• Voltage to Temperature
• … and more

Starting from the DashDAQ Main menu:
Press [Setup] then [Devices] then [Manager].
Select an unused location such as "f-UNUSED" by touching the line with this text.
Press [Add Device].  Use the top right or left arrow buttons to choose "Calculator" at the top.
Select "Rescale Signal Calculator" from the list and Press [Install].
Press [OK] then [Exit].

Starting from the DashDAQ Main menu:
Press [Setup] then [Devices] then [Parameters].
Move left or right and choose "X-Rescale Signal Calculator".  (X is the letter of the device added in Step 1)
Select "Input Signal" then press [Change...].
Move left or right to select "d-Zeitronix Zt-2".  (select "e-Zeitronix Zt-2" to rescale values on a second Zt-2)
Select "Analog Input 1", "Analog Input 2", "AFR", or any other value you with to adjust then Press [Save].

NOTE: Analog Input 1 is the Zt-2's "User" input,  Analog Input 2 is the Zt-2's "User2" input.  The User1 input is always a 0-5 volt voltage value from the Zt-2.  The Zt-2 User2 input can be configured through the Zeitronix Data Logger to output values as temperatures or pressures directly.  The rescale signal calculator is not needed if the values are already being converted in this manner.  Viewing the Zt-2 "Analog Input 2" data will show the data in the temperature or pressure configured through the software.

Next select "Multiplier Signal" from the list and Press [Change...],
At the top move left or right to select "X-Rescale Signal Calculator".
Select "Constant Multiplier" and Press [Save].

Next select "Offset Signal" from the list and Press [Change...],
At the top move left or right to select "X-Rescale Signal Calculator".
Select "Constant Offset" and Press [Save].

Next select "Constant Multilier" from the list and Press [Change...],

At this point you need to enter a multiplier to convert the Zt-2 data to another value:

If you selected "AFR" as the input signal and are converting to lambda then enter a value of 0.068 ( 1/14.7).  This multiplier will convert an AFR value to a Lambda value.

If you have attached a pressure sensor or temperature sensor this multiplier will depend on the exact sensor specifications being used.  Use the sensors range and calculate the multiplier as follows:

For a Zeitronix 50 psi (3.5 bar) MAP sensor the multiplier would be:
   multiplier = 50 psi / (4.5-0.5 volts) = 50 psi / 4 = 12.5 psi per volt
or
   multiplier = 3.5 bar / (4.5-0.5 volts) = 3.5 bar / 4 = .875 bar per volt

For a Zeitronix 75 psi (5.0 bar) MAP sensor the multiplier would be:
   multiplier = 75 psi / (4.5-0.5 volts) = 75 psi / 4 = 18.75 psi per volt
or
   multiplier = 3.5 bar / (4.5-0.5 volts) = 5 bar / 4 = 1.25 bar per volt

For a Zeitronix 150 psi (10 bar) gauge sensor the multiplier would be:
   multiplier = 150 psi / (4.5-0.5 volts) = 150 psi / 4 = 37.5 psi per volt
or
   multiplier = 10.34 BAR / (4.5-0.5 volts) = 10 bar / 4 = 2.585 bar per volt

After entering the multiplier number Press [Save]
Move down the list and select "Constant Offset" and Press [Change]

The value entered here is sensor dependent.  The DashDAQ is computing the following
   final value = multiplier x (Zt-2 data) + offset

If you selected "AFR" as the input signal then enter a value of 0 here for the constant offset.

For other Zt-2 sensors we can calculate the required offset as follows:
offset = pressure - multiplier x voltage

For a Zeitronix 50 psi (3.5 bar) MAP sensor the offset would be:
   offset = 0 - 0.5 volt * 12.5 psi per volt = -6.25 psi
or
   offset = 0 - 0.5 volt * .875 bar per volt = -.4375 bar

For a Zeitronix 75 psi (5.0 bar) MAP sensor the offset would be:
   offset = 0 - 0.5 volt * 18.75 psi per volt = - 9.375 psi
or
   offset = 0 - 0.5 volt * 1.25 bar per volt = -.625 bar

For a Zeitronix 150 psi (10 bar) gauge sensor the offset would be:
   offset = 0 - 0.5 volt * 37.5 psi per volt = -18.75 psi
or
   offset = 0 - 0.5 volt * 2.585 bar per volt = -1.29 bar

After entering the constant offset number Press [Save].
Press the down arrow on the left to scroll down and select "Name".
Press [Change] to enter a new name for this value.  Press [Save] to save it.
Press the down arrow on the left to scroll down and select "Units".
Press [Change] to enter new units for this value.  Press [Save] to save it.
Press the down arrow on the left to scroll down and select "Precision".
Press [Change] to enter the new number of decimal points which should be shown for this value.
Press [Exit].

Select a gauge or digital display item for viewing the rescaled value by touching it.
Move left or right at the top to choose "X-Rescale Signal Calculator" (X is the letter of the device in Step 1).
Select "Calculated Value" (or the name you entered for the value) from the List.
Press [Save].
Enter High and Low limits for the value.
Press [Save]

The new value and units will be shown on the display.