I am using a CANCase VN1640A between 2 ECUs in order to falsify a CAN message. Below the bridge simulation setup:
In my CAPL Code, the received messages from channel 1 will be redirected to channel 3 and vice-versa. (So far I am not falsifying any message)
variables{
message can1. msgCAN1;
message can3. msgCAN3;
}
on message can1.{
msgCAN3=this;
if(this.dir == rx)
output(msgCAN3);
}
on message can3.{
msgCAN1 = this;
if(this.dir == rx)
output(msgCAN1);
}
But when I start CANoe I get this Error message:
This error means that CANoe tries to send more as it could. The transmit buffer is overflowed. I have changed the hardware configuration of Transmit Queue size to the max 32768 messages, also the Receive Latency to very fast but unfortunately the error occur again.
Does anyone have any hints that could help to solve this problem and thanks in advance.
The error message can mean, that CANoe tries to send more as it could. The transmit buffer is overflowed. This can have several causes:
the bus is full of high prior messages and therefore CAN hardware cannot send
You have a program which writes messages very quick to the buffer, so that the card can´t send (while loops for).
Error frames occur when sending and thus the card cannot send.
Vector tool provides a loop test:
Send messages from CH1 to CH3. If this is working fine, it looks like the problem is caused by your CANoe configuration.
The necessary test programs are part of the Vector Driver Setup Files and located in the folder Common. You can download the Driver Setup File from www.vector.com/driver-setup.
CAN Highspeed Looptest: http://kb.vector.com/entry/589/
CAN Low-speed Looptest: http://kb.vector.com/entry/590/
If the loop test works fine, you can see the time, the busload etc. If not, you will get a failed message.
Note:
Reduce the number of channels used in CANoe/CANalyzer under:
Configuration | Options | Measurement | General | Channel usage.
Are there more selected channels in the CANoe configuration than assigned CANcabs in the Vector Hardware Config?
(Start | Control Panel | Hardware and Sound | Vector Hardware)
Please check the channel and application assignment in the Vector Hardware Config.
Kindly check the hardware mapping in CANoe. This error mostly arises when the mapping is not correct or disturbed.
Go to Hardware-> Network Hardware configuration -> Driver -> Select proper channel for the vector hardware
I hope this helps !
So this error does NOT mean that CANoe tries to send more as it could.
It means instead:
We have (many) error frames on the CAN bus. CANoe tries to send messages which does not work (for whatever reason) -> error frames are the result. The CAN controller will retry to send the frame which might again lead to an error frame. Now over time the Send Requests accumulate and lead to further error frames. At some point the buffer for the error frames does overflow which leads to the message you see in the write window.
Solution:
We have to check the Trace Window and check what kind of error frames we get there (and then take suitable measures to prevent them).
Related
Hello everyone and thanks in advance for the help,
I am using the WriteFile function (fileapi.h) to send frames to the NDIS driver at Ethernet Layer 2 level, directly between MAC addresses.
The frames are sent correctly, but in any of the tests I did, the frames are sent duplicated. I detected this by capturing the output with WireShark, where the following is represented:
Within the frame I send, I increment a counter on each send. This counter is repeated in two consecutive frames, which have different frame numbers assigned by WireShark.
This is not something that happens randomly due to the loss of messages in the network, and the forwarding of messages by another device in the network. It happens on every frame that is sent, they are exactly the same, including the counter which is incremented every two frames.
Questions:
Is there a parameter in the NDIS driver that sets this duplicate output.
Am I misinterpreting the WireShark capture.
I saw this post, and did as recommended by uninstalling and installing Ncap and WinCap, but it made no difference.
Thank you very much. Best regards.
bSuccess = (BOOLEAN)WriteFile(
Handle,
pWriteBuf,
PacketLength,
&BytesWritten,
NULL);
DWORD err = GetLastError();
printf("ERROR: %i", err);
if (!bSuccess)
{
PRINTF(("DoWriteProc: WriteFile failed on Handle %p\n", Handle));
break;
}
Solved, I answer to my question.
The compilation of the NDIS driver that I am using, comes prepared with the NDIS_SEND_FLAGS_CHECK_FOR_LOOPBACK flag in the send.c file.
For this reason, and following the explanations of this page, it is possible to cancel the duplicated messages in the computer of origin, since in the computer of destiny, finally these did not arrive to be an internal loop.
Best regards.
I am using CANalyzer.
I am transmitting CAN message using Interactive Generator block. I use IG to modify signals in transmitted message by hand.
I need to automaticaly calculate checksum (the last byte in the message) every time the message is sent. Checksum is calculated from all previous data bytes in the message (message is always 8 bytes long). There is no option in IG to do that.
I need:
Set signals by hand using IG.
Automatically calculate value of the last data byte according to values of preceding data bytes.
I tried to write simple code in CAPL but without success.
I put CAPL Program node after the IG node in the Configuration window and wrote on message event in CAPL script:
on message FooMsg
{
message FooMsg msg1; // FooMsg is name of message in database
msg1 = this; // copy message from IG to temporary variable
// this.byte(7) = 0x11; // not posibble, compiler warning
msg1.byte(7) = 0x11; // constant value just for test
output(msg1); // send message
}
The message is transmitting but the Tx period set in IG is not respected (message is transmitted as fast as possible).
I thought I catch the message generated from IG, modify it and send to CAN bus.
Finally, I redesigned the whole stuff as VioletVynil recommended.
I created panels, add system variables and hooked them to controls on panels, wrote some code in CAPL for calculating checksum and periodic transmit of the message and it runs! Without any problems! And yes additional CRC on the payload is used for additional safety (railway application). I didn't designed communication protocol, I just got it.
I have a configuration setup with two CAN nodes and an attached database. I have added a CANOEILNLVECTOR.dll to both the nodes. By adding this Dll file all my messages are sent cyclic as I see in trace window.
Now I set some value for a signal in a message, For Eg:
variables
{
message Battery_Traction Batt_msg;
}
on start
{
Batt_msg.Isolation_Signal = 0x02; //0x02:On
output(Batt_msg);
}
What I see on trace is: The message is cyclic but only for the first instance the value set by me above appears in trace. For all of the rest times the signal value in the message in set to default.
As seen in the image value 0x02 is sent only once.
I am not sure what could be the problem, as seen in image attached value set by me is only sent once.
When using output you are putting the message directly onto the CAN bus, but you are not changing the value inside of your (simulated) node, so the interaction layer is still sending the old value.
You can change the signal value in the interaction layer by just putting a $ in front of the signal name and set the value.
In your case most likely $Isolation_Signal = 0x02
Outputting the message on the CAN bus at the right time, with the right cycle time and so on will be handled by the interaction layer.
You have two ways to influence dynamically the value of your message: IL DLLs and custom message sending.
Custom message sending is the basic way, where
you define the message ex.: message Battery_Traction Batt_msg;
you trigger its sending(output function)
you set up cyclic sending on timer Cycletimemsg1 {output(msg1);}
and so on.
IL DLLs are doing this all for you, without much coding effort from your side, but they rely heavily on the dbc settings and attributes you have linked as database to your CAN Channel.
Unfortunately, they don't play well together, meaning you need advanced CANoe know-how of them to use both in the same environment. You basically bypassed your CANOEILNLVECTOR.dlls working by sending explicit message.
So your code if you are accessing your signal through IL, should look like this:
variables
{
/*no need to define custom message object, they are already "known" to IL by dbc*/
}
on start
{
$Batt_msg::Isolation_Signal = 0x02; //0x02:On
/*NO need for output either (IF YOUR MESSAGE IS defined Cyclic in dbc), */
}
If your signal is not identified at $Batt_msg::Isolation_Signal, just dragndrop the signal from the CAPL browsers Symbols panel, and add the $ sign before it.
Through dollar($) sign, you access the dbsignal class objects signal value attribute.
Subject: Unable to reset the can error using CAN bus error recovery sequence. As when the can bus is not connected to other node .
Description:
We are using infineon XE164 micro-controller and keil uvsion4 for compile the code.
BACKGROUND AND THE HARDWARE SETUP
Our product setup is as below:
We are using XE164 micro-controller to control peripherals . In peripherals it basically control the servo motor , stepper motor , lcd and keypad.
We want to transmit data from infenion XE164 node to PIC18f2480 node.
PROBLEM
There is no issue to transmit and receive data from both node on can bus.
When bus is not connected and data is transmitted by XE164 board our can bus goes in error state.what is recovery sequence to change the can bus mode in error state to idle state.
How to avoid this without hardware reset of micro controller.
In CAN protocol, ACK is a must!
If there is no other node on the bus, CAN Transmission will not work and it's a correct behaviour that it goes in error state.
Only way to get rid of that error state is re-initializing your CAN module (like calling CANInit() again), because even after error recovery sequence, CAN controller retries to transmit the data and again gets stuck into Error state and this will go on... Re-initialization will stop its attempts and CAN module will be in normal state.
EDIT after comment from OP:
If you want to poll whether there is a device on bus or not, you can set a Timer interrupt of say X msec and in Timer ISR:
1. Initialize CAN
2. Send a CAN Message
3. If no error interrupt is generated and message is successfully transmitted, stop timer otherwise keep it going.
You can also try different baud rates too.
If I sent a lot of messages to a remote node and immediately call erlang:disconnect_node/2 to drop the connection, is there a chance some messages don't get through the wire? In other words, does that method perform a brutal disconnection, regardless of waiting messages?
No, even with two local nodes!
Setup: I got a node a#super, on witch a dummy receive-print loop runs, registered with a. On another node, I run
(b#super)1> [{a, a#super} ! X || X <- lists:seq(0,10000)], erlang:disconnect_node(a#super).
That is, many messages, and then a brutal disconnection.
Result: the receiver printed the full 10001 messages only once over 10 runs.
So, you definitely do not have any guarantee the receiver got all the messages. You should use another technique (novice at erlang, sorry), or use an ack message before the disconnect.