PEAK-System Forum

Hello,

I'm using this interface for a project at my university. I have other devices on the bus and I can monitor their activity using PCAN-View if I set the PCAN-PCIe card to listen-only mode, but whenever I try to send something on the bus (not using listen-only mode, obviously) I get a status: Error Passive. I'm wondering what could be causing this issue and how could I solve it? Any help would be appreciated.

Regards,
Alejandro

Hi,

please check your CAN cables for correct termination. Next, please verify which baudrate settings (samplepoint etc.) is used on your CAN bus by the different CAN nodes. You can modify the used baudrate from the default value to the needed values by selecting a BTR0BTR1 value. Use the baudtool from our support website to calculate the baudrate settings you need.

regards

Michael

Hi,

thanks for the quick response. I have a couple questions. This model has an 8 MHz clock frequency, right? Right now, the bit timing parameters are: prescaler=1, tseg1=5, tseg2=2 and sync jump width=1. I believe these are the default parameters for a 1 Mbps transmission with a 75% sample point.

Is it necessary for the different nodes connected to the bus to have the same sample point? As far as I understand the only requirement would be for them to have the same baud rate, in this case 1 Mbps.

If there was a problem with the cables and their terminations, wouldn't it be impossible to check the activity on the bus even in listen-only mode?

Also, regarding the connection to the bus, right now I only have pins 2,3 and 7 (CAN-L, GND and CAN-H respectively) from the DB9 connector connected to the bus. Is this enough or do I need to use pin 6 (also GND) to the common ground?


Regards,
Alejandro

Hi,

the used oscillator frequency is depending on the used PCAN-hardware. Please provide the serialnumber of your card, to be able to see which hardware version you are using. Typically on SJA1000 based cards, 16Mhz will be used.

For a working CAN communication all nodes should use the same bitrate settings (baudrate, samplepoint, sjw etc.).

When there is a baudrate missmatch, you will receive no valid CAN frames (even in LO mode), only errorframes.

You need to use CAN-L and CAN-H for a working communication. CAN-GND is optional. However, it is necessary to have 120 Ohms termination resistors on both ends of your CAN cable between CAN-L and CAN-H, otherwise no CAN communication will be possible.

regards

Michael

Hi,

I've solved the problem now. It was caused do to faulty wiring, but everything is working fine now. Thank you very much for your help.

Regards
Alejandro

Hi Everyone,
@Alejomg, I am facing the same issue of passive error warning.

I am connecting PCAN USB FD with MK22FX512 Microcontroller(CAN) and want to make CAN communication. If I try to transmit or received the data, The LED on PCAN USB FD is become RED and PCAN View is showing Passive error warning.
How can I resolve this issue ?

Any help is appreciated and will be thankful.

Best Regards

The red LED on the PCAN-USB FD shows that your CAN System have a problem.

Simply check the CAN Basics - which will solve 100% your problem

* Termination
* A CAN Network need minimum 2 activce nodes (otherwise noc ACk - if no ACK --> ERRORS)
* Check the Timing ! CAN FD is very sensitive if the timing is not 100% correct!

But all these infos are posted in this forum hundred times
Also: you post in a PCI-Express part - not USB-FD ....

David wrote: ↑

Fri 28. Jun 2019, 10:48

Hi Everyone,
@Alejomg, I am facing the same issue of passive error warning.

I am connecting PCAN USB FD with MK22FX512 Microcontroller(CAN) and want to make CAN communication. If I try to transmit or received the data, The LED on PCAN USB FD is become RED and PCAN View is showing Passive error warning.
How can I resolve this issue ?

Any help is appreciated and will be thankful.

Best Regards

Hi David,
I met same problem as yours with same device, did you solve it? If yes, could share with me how? Thanks!

see our answer - this will also be help in you system.

The red LED on the PCAN-USB FD shows that your CAN System have a problem.

Simply check the CAN Basics - which will solve 100% your problem

* Termination
* A CAN Network need minimum 2 activce nodes (otherwise noc ACk - if no ACK --> ERRORS)
* Check the Timing ! CAN FD is very sensitive if the timing is not 100% correct!