Using 2 USB Adaptors

[p.erasmus]

I am using the PCAN Basic API with a USB adaptor which is working just fine, however I would like to
connect to a second CAN bus with a second adaptor running in the same Application software ,I would like to use the Application software as a gateway between the 2 systems
is this possible to do or do I have to use the Developer API ?
if it is possible with the Basic API is there a example some were?
Thank you for the support

[K.Wagner]

Hello Peter,

you are able to use up to 8 USB channels simultaneously within the same application using the PCAN-Basic.

We don't have an example doing this, but basicly you just need to make the connection process you have written in your app twice, one for each adaptor (CAN-Bus):

// PCAN-USB connected to the CAN-Bus A
PCANBasic.Initialize(PCANBasic.PCAN_USBBUS1, TPCANBaudrate.PCAN_BAUD_500K);

// PCAN-USB adaptor connected to the CAN-Bus B
PCANBasic.Initialize(PCANBasic.PCAN_USBBUS2, TPCANBaudrate.PCAN_BAUD_500K);

Then, you have to modify the way you read and write. You have to read from a channel and immediatly write to the other:

// Read from CAN-Bus A
PCANBasic.Read(PCANBasic.PCAN_USBBUS1, out CANMsg);

// Write to CAN-Bus B
PCANBasic.Write(PCANBasic.PCAN_USBBUS2, ref CANMsg);

Take into account that the PCAN-Basic does't allow you to write messages associated to a timestamp, so that the times between messages could be different when you re-write them to the second bus.

I hope this help. Good luck

[p.erasmus]

Then, you have to modify the way you read and write. You have to read from a channel and immediatly write to the other:

Mr Wagner thank you for you example and efforts to help !!
I appoligisize if my statement regarding the gateway functionallity was misleading ,I want to read data from the 2 Busses ,at the moment i use your interrupt callBack to read CANA ,do I have to set up a second callBack for CANB ,The info you have given for connecting to CANA and CANB is very helpful and thank you very much for it.
I am not a windows programmer or software developer so I always have problems to understand how to implement the ideas is software examples like you showed me in your post is very much appreciated

Best regards
Peter

[K.Wagner]

Hi Peter,

...at the moment i use your interrupt callBack to read CANA ,do I have to set up a second callBack for CANB ...

If you mean with "interrupt callback" the function "ReadMessages" from the PCAN-Basic samples, it is up to you if you do the new read works within the same function or in a new one. To read from the second adaptor you have to do just the same steps, but using the handle of the new USB-Channel. Taking as example "reading with a timer" from the PCAN-basic samples (I will use C#), you could modify the code a little to get what you want:

Code: Select all

       private void tmrRead_Tick(object sender, EventArgs e)
        {
            ReadMessages();
        }

you could change the code above to do something like this:

private void tmrRead_Tick(object sender, EventArgs e)
{
ReadMessagesFrom(PCANBasic.PCAN_USBBUS_1);
ReadMessagesFrom(PCANBasic.PCAN_USBBUS_2);
}

and this function...

Code: Select all

        private void ReadMessages()
        {
            TPCANMsg CANMsg;
            TPCANTimestamp CANTimeStamp;
            TPCANStatus stsResult;
	
            do
            {
                stsResult = PCANBasic.Read(m_PcanHandle, out CANMsg, out CANTimeStamp);

                if (stsResult == TPCANStatus.PCAN_ERROR_OK)
                    ProcessMessage(CANMsg, CANTimeStamp);

            } while (btnRelease.Enabled && (!Convert.ToBoolean(stsResult & TPCANStatus.PCAN_ERROR_QRCVEMPTY)));
        }

... could be changed to receive a parameter (channel):

private void ReadMessagesFrom(byte channelHandle)
{
TPCANMsg CANMsg;
TPCANTimestamp CANTimeStamp;
TPCANStatus stsResult;

do
{
stsResult = PCANBasic.Read(channelHandle, out CANMsg, out CANTimeStamp);

if (stsResult == TPCANStatus.PCAN_ERROR_OK)
ProcessMessage(CANMsg, CANTimeStamp);

} while (btnRelease.Enabled && (!Convert.ToBoolean(stsResult & TPCANStatus.PCAN_ERROR_QRCVEMPTY)));
}

Best regards,
Keneth

[p.erasmus]

Hello Keneth

Thank you very much for your help it is highly appreciated ,You do not now how much you helped me
you guys at Peak are unbelieveable !!!

Have a nice weekend