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DC Voltage on CANBUS from RNS-E

2370 Views 3 Replies 2 Participants Last post by  PetrolDave

Further to my install issues I decided to bench test my unit and confirm the functionality of my RNS-E.

All ‘works’ as expected.

I subsequently decided to check the CANBUS output of the RNS-E due to the fact that the last time I attempted to install this unit it ‘f****d up’ my instrument cluster.
Now I have a new cluster, I want to keep it a while, so I checked the CANBUS with my Fluke 87 multi meter. I was surprised with the result as I haven’t read anything about this on this forum. I will be ‘scoping’ the CANBUS for data tomorrow.

CAN H and CAN L there is a differential of 10.43 V DC

CAN H and Kl.31 Ground 0.255 V DC
CAN H and Kl.30 Con 12V 11.13 V DC

CAN L and Kl.31 Ground 10.92 V DC
CAN L and Kl.30 Con 12V 0.322V DC

Are the above voltage differentials typical of RNS-E units or have I found my cluster killer?
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According to the CAN bus specifications the difference in the voltage between CAN high and low should be between 1.5V and 3V, and the actual voltage should be between 2V and 3V.

So it looks like your CAN bus voltages are wrong. Could be your cluster killer...
Thanks Dave

Please could you let me know where I can obtain the CANBUS spec.

Also to the Navplus community:

Has anyone measured their RNS-E CANBUS connections?

krammer002 said:
Thanks Dave

Please could you let me know where I can obtain the CANBUS spec.

A search on Google also finds the datasheets of CANbus interface devices which give additional information.
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