Lucie
11-10-2010, 01:12 PM
Reading RPM using Micro Input Module
To set this up in the VVB Setup software you would have to do the following:
a. Expand 'CAN and module configuration' and 'Micro Input Module' under scene properties and click one of the channels. When the next window appears, you have to tick ‘Log’ is the top right hand corner. You can also change the name of the channel to 'RPM' if you wish.
b. Select the RPM gauge you wish to use and expand the 'background' section under gauge properties. Here you can set the parameter to the channel you have chosen to log. Make sure the min and max values are correct and match the text on your gauge image.
You need to keep in mind that when you have connected your Micro Input Module to your vehicle, you need to set a scale and offset in the scene to allow it to work correctly for your vehicle.
You can do this by clicking on the Micro Input Module channel that the RPM is being read from, then in the window that appears you will have the option to set scale and offset values.
For most vehicles, the way you need to calculate what this scale needs to be is to divide 120 by the number of cylinders in the engine.
This is because the Micro Input Module gives pulses per second which we need to convert into revolutions per minute.
So, for example the calculation for 1 pulse per second would be as shown below.
1 pulse per second x 60 = pulses per minute x 2 (because 2 revolutions of crankshaft per combustion of spark plug) = 120. This then divided by the number of cylinders (4) = revs per minute - 30
So, for a four cylinder engine it would be 120 divided by 4 = 30
A six cylinder engine would be 120 divided by 6 = 20
When this is all set up you can take a digital pulse signal from a source such as an ECU to tachometer cable, or the negative side of a coil signal in your car and connect it to the correct channel on the Micro Input Module.
I hope this is useful!
:D
To set this up in the VVB Setup software you would have to do the following:
a. Expand 'CAN and module configuration' and 'Micro Input Module' under scene properties and click one of the channels. When the next window appears, you have to tick ‘Log’ is the top right hand corner. You can also change the name of the channel to 'RPM' if you wish.
b. Select the RPM gauge you wish to use and expand the 'background' section under gauge properties. Here you can set the parameter to the channel you have chosen to log. Make sure the min and max values are correct and match the text on your gauge image.
You need to keep in mind that when you have connected your Micro Input Module to your vehicle, you need to set a scale and offset in the scene to allow it to work correctly for your vehicle.
You can do this by clicking on the Micro Input Module channel that the RPM is being read from, then in the window that appears you will have the option to set scale and offset values.
For most vehicles, the way you need to calculate what this scale needs to be is to divide 120 by the number of cylinders in the engine.
This is because the Micro Input Module gives pulses per second which we need to convert into revolutions per minute.
So, for example the calculation for 1 pulse per second would be as shown below.
1 pulse per second x 60 = pulses per minute x 2 (because 2 revolutions of crankshaft per combustion of spark plug) = 120. This then divided by the number of cylinders (4) = revs per minute - 30
So, for a four cylinder engine it would be 120 divided by 4 = 30
A six cylinder engine would be 120 divided by 6 = 20
When this is all set up you can take a digital pulse signal from a source such as an ECU to tachometer cable, or the negative side of a coil signal in your car and connect it to the correct channel on the Micro Input Module.
I hope this is useful!
:D