XNET CAN current leak

[Madottati]

We have a PXI 8516 card where we use both CAN and LIN. At the end of the functional test of the DUT, we measure quiescent current, which is normally around 40 microampere. We measure 120 microampere, if the XNET CAN is physically connected. If we disconnect it, the current is 40 microampere again.

My question is, where the additional current comes from? Is it a known issue on XNET?

regards

Madottati

[Hooovahh]

For our ECUs they wake on CAN traffic.  The ECU will continually send out CAN data, and if a transceiver is on the bus that reads those frames, then the ECU stays awake and keeps transmitting data.  Only after going through the shutdown process, and stopping all XNet sessions, does our ECU actually go into the low power mode and draw the amount of current that is typical.  I don't know if NI has more information, but for us this was one thing we had to work around.  With our setup and XNet connected, we are able to measure down to the about 50 microamp draw with it still physically connected.  Also are you using the termination feature of the XNet device?  I wonder if this is effecting the readings somehow.