Usage of AVTP and Hardware-based send scheduling with VN5610
CANoe.Ethernet supports hardware-based send scheduling together with the VN5610 interface hardware. Due to hardware-specific restrictions the usability of this feature for AVB/TSN is limited by the following factors:
- The number of concurrent simulated AVB talkers (sending streams on the same interface hardware channel)
- The bandwidth requirement of each stream (packets per second and bytes per packet)
Typically these restrictions allow for sending one or more uncompressed audio streams on the same hardware channel.
No traffic shaping is performed on a send port, neither in hardware nor in software.
The VN5610’s send timing precision is only guaranteed when one talker is sending one stream exclusively on a single channel.
Beginning with CANoe version 11 SP2 software-based send scheduling can be used instead to work-around these limitations. Hardware based send scheduling provides less accuracy of the send intervals but should be sufficient for most streaming scenarios with higher bandwidth requirements such as video streaming.
If you get the following error message while sending an AVTP based network video stream on a Real Bus connected with a VN5610:
System 44-0001 Ethernet Driver: [Eth 1] Time 566.804 Eth 1 TX-Error: Invalid schedule timestamp.
CAPL / .NET VAvbLayer: errorCode equals 7
Proceed as follows:
- download and install at least CANoe 11 SP2 from our Download Center
- add in the following section to CAN.ini:
- You can check the CAN.ini location in your installation like following:
After that, you should be able to read the following message in the write window after the measurement start:
Ethernet interface does not support hardware-based send scheduling. Software timed-scheduling with limited accuracy is used.
- For talkers that send RTP streams software-based time scheduling is always used, regardless of the CAN.ini setting.
- For the VN5640 interface hardware-based send scheduling is not available.