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Unit of Measurement in CAN communication

PostPosted: Tue Apr 17, 2018 7:08 am
by mr2andy
Hello all,
I'm using the Motec M400 CAN Template #1 to send sensor information to ADL2 and I'm experiencing some unit of measurement issue.

For example, if I'm sending Fuel Pressure in PSI ~40psi from M400 to ADL2, in ADL2, it's showing 40kpa and if I then specified the unit to be shown in psi, ADL2 will then convert the 40psi value to psi again and showing 6psi.

Where can I specified in ADL2 that when receiving the Fuel Pressure from M400 Can massage, it's already in PSI unit instead of kPA.

Re: Unit of Measurement in CAN communication

PostPosted: Tue Apr 17, 2018 10:17 am
by adrian
The ECU will send the CAN message in what ever unit you have specified, so in this case PSI. However, in the background all channels in the Dash use SI units. Then if you select PSI as the displayed unit it converts from kPa to PSI. In this case as the actual channel value is sent in PSI the conversion doesn't work.

To get around this you have to convert the CAN signal from PSI to kPa in the CAN setup. To do this, edit the M400 CAN template, find Fuel Pressure and change the Multiplier to 1000 and the Divisor to 145. Now the channel value will be in kPa in the background but will correctly convert to PSI on the display.