NI XNET diagnostic frames Slave Response ISSUE

[DARDARDAR]

Good morning,

I have an issue with LIN Slave Response.

I'm using NI USB 8506 device with XNET driver and Labview 2016 software.

What I am supposed to do:

1- Write a CAN message to DUT (with Vector VN1610 device)

2- The DUT (MASTER) forwards the message to LIN BUS as a Master Request

          Message with ID 0x3C and 8 bytes of payloads

3- The NI USB 8506 (SLAVE) has to read the message

4- I have to emulate-TransmitToMaster_DUT with NI USB 8506 (SLAVE) a Slave Response

          Message with ID 0x3D and 8 bytes of payloads

5- The DUT reads the response on LIN BUS and forward the message on CAN BUS

Everything is working well till point "3-". It is not clear how to emulate-transmit the Slave Response to the LIN Master --> DUT.

I have opened 4 sessions:

I- LIN1 of NI USB 8506 -- Frame IN Stream

II- LIN1 of NI USB 8506 -- Frame OUT Stream

III- LIN2 of NI USB 8506 -- Frame IN Stream

IV- LIN2 of NI USB 8506 -- Frame OUT Stream

To execute point "3-" I simply use "XNET Read" block with "Frame LIN" of session "I" because I'm using LIN1 interface.

Can the message (ID and payload ) I read from point "3-" be considered as a Master Request?

It seems that I cannot transmit the SlaveResponse on LIN BUS because the BUS MONITOR does not log any TX message.

Can anyone give a suggestion?

Thanks in advance

[TroyK]

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"Can the message (ID and payload ) I read from point "3-" be considered as a Master Request?"

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For a LIN bus all messages must be initiated by the Master. Is the Master initiating the response by sending the 0x3D header byte?

Are there any errors? 0x3C & 0x3D are designated as diagnostic frames and may not have the same checksum calculation as other messages (always classic for diagnostic frames).

[DARDARDAR]

Good morning Troy,

yes I have seen with oscilloscope that the Master (DUT) is sending periodically (every 10ms) the 0x3D header (for a total time of 5 seconds, after that time the Master seems to go in Sleep and no any action is further possible...anyway), but it is not clear how to say to the Slave (NI USB 8506) to answer.

Or better, to append the Payload to the Header sent by the Master.

Any suggestion about this?

Thanks in advance

[TroyK]

I haven't used a NI USB 8506 before but I know that the Slave response needs to be buffered (or queued) in the slave device before the Master sends out the header byte so that response can come out immediately in real-time.

Are you getting any errors when setting the slave response?

Have you followed the advice here: https://zone.ni.com/reference/en-XX/help/372841M-01/nixnet/usinglin/

[TroyK]

I just re-read your initial post. Are you seeing the LIN Master request message and payload (0x3C) on the NI LIN bus monitor, not just the oscilloscope?

If not, make sure the LIN Master and Slave bus grounds are connected.