measure the CAN bus data in DMM

[Sumithra_Nagappan]

Hi

 I need to do a loopback verification in CAN and verify the same using DMM-4071.

 I have gone through XNET  examples for CAN Loopback ,it is working.But i need someone's help in verify the output in DMM.Can anyone suggest few ideas to measure the CAN bus data in DMM

[Hooovahh]

Well a DMM traditionally is quite slow.  It generally does DC averaging all the time.  Some nicer ones are able to detect frequency and duty cycle of a signal, but for this to get a lock on the signal it needs to maintain this on the order of seconds.  And a CAN signal, even at the lowest baud, is going to take much less than that.  No DMM will be usable to verify a CAN signal.

You'll need a scope.  Some expensive scopes have a CAN port built in where it can analyze the signal and look at rise and fall times, in addition to parsing the bits into a usable frame.  But even so this is overkill.

If you want to verify a CAN bus is working, plug in a off the shelf CAN device and see if the message makes it.  There are other steps you could perform of couse but it is a start.