CAN@Net NT 200 Throughput


#1

I have an CAN@Net NT 200 card. I have the card setup as an ASCII Gateway. What kind of transmission rate limit can I expect from the card?

It appears with the card receiving 4 CAN IDs of 8 bytes each at 200 Hz that the received information is not consistent.

Is there a better method to receive data?

Thanks,
Eldon


#2

Hello @eldonz,

As mentioned over the phone I have created an internal ticket to investigate this issue. Once I have reviewed this with my colleagues in Germany I will follow up with you.

Regards,
Deryck


#5

Deryck,

Any update?

Thanks,
Eldon


#6

Apologies I had messaged you through the support ticket I had made for this issue. Here is the message I sent you earlier in the week.

Would you be able to provide a description of the inconsistent data you are getting from the CAN@net? My colleagues are looking for more detail then what I was able to provide following our phone conversation.

I believe you discussed this issue with the TCP stack but I want to make sure you still have this info from my colleagues.

The ascii interface is a standard TCP port.
The user, who implements an application on the ascii interface, should be aware of some common issues of TCP.
See for example the document from Microsoft:
Design issues - Sending small data segments over TCP with Winsock
https://support.microsoft.com/en-us/help/214397/design-issues-sending-small-data-segments-over-tcp-with-winsock

This document handles also the “200ms delayed ACK” mechanism of TCP. To work around this, you can do:

  1. disable the delayed ACK on the host machine for the whole network adapter:
    See for example: http://freevbsite1.blogspot.com/2015/07/disable-tcp-ack-delay-time-on-windows-7.html

  2. Send cyclically (e.g. 30ms) a message from the host machine e.g a CAN status request (“CAN 3 STATUS”).
    This request/response messages work around the 200ms delayed ACK