NI USB 8476 communication

[andrea080690]

Hi, I am trying to send an header message to a device with an NI USB 8476 using a Labview program found in this forum. I have readed the device's spesification but when I try to send a header message to the device I have a LIN BUS Error. I send attached the images of the spesification and the program. Someone know why I could have the BUS Error? 

[JefeL]

Page 10-102 of the manual describes the error codes shown in the shipping example. Bit 0 and 1 in your screen cap correspond to 0x8400 or LinBusErrorNoResponse. 

From what I can tell the header was sent out but no slave on the bus responded to it. This is most likely due to a problem with the slave ECU, not having the slave connected to the bus, or not powering the slave.

[andrea080690]

I am still trying to send LIN message to the device. Finally I think I have send it something but I am not able to reproduce it another time. As you can see in to the picture after an error (10 80 02 00), a message with 4 bytes, I was able to send a LIN message with 8 bytes. Sameone know what could be or how can I reproduce it? Thanks.

[andrea080690]

I found the error (10 80 02 00) happens because there is no voltage, so the device could be in a normal mode for a few second and then goes in a sleep mode? 

[JefeL]

The error code 1080 is indicative of a catastrophic bus failure such as the LIN bus being externally pulled dominant (low).

[andrea080690]

Yes, I know, it is because I turn off the power, but after it, the device answere to a command as you can see. That vould be because lin device goes in sleep mode usually after 4 seconds.

[JefeL]

Neither the master nor the slave should ever hold the LIN line in a dominant state so this behavior is very strange. 

Per the LIN standard, slaves will typically put themselves to sleep after 4 seconds but should also release the LIN line so it can be pulled high. The NI-CAN master will indicate that it is "Asleep" but in reality the controller remains in a semi-awake state that allows it to respond to commands from the host PC. The master can be explicitly put to sleep if the user chooses to do so by sending a sleep command.

[andrea080690]

Thanks for the answere; rarelly I am able to send a LIN full frame as you can see in to the picture. The problem is that most of the time not, and even if I send the message the slave doesn't responde.

I am able to send a LIN message when i send the same ID in to the "Slave Response Frame" and in the "ID for header", bur, most of the time when I try to send for example 3C ID to the Slave Reponse Frame, than I can't use the same 3C ID for the Header.

[andrea080690]

Another problem I have is that in the specification I can't find the wakeup frame. Sameone know if there is a standard wakeup frame for LIN communication? Or where can I find it? Thanks.

[andrea080690]

Sorry for many questions, it's my first time programming lin and using USB 8476. In the picture, in the red square should I see the device response right?

Because now I can send lin message with the USB as you can see but I don't recive any response.