CANServer v2 Network
The Network screen allows you to view and make changes to the Networking related features of the CANServer
The Internal Wireless Connection section shows the current status (and IP) of the internal private wireless network.
You can also change the SSID and Password used for the internal private wireless connection. Note that if you change from the defaults you will not be able to use microDisplays as they are hard coded to use the default credentials
The Hostname parameter lets you change the name that the CANServer will advertise. CANServer uses mDNS (zeroconf, bonjour) to broadcast some defined services (_panda._udp., _http._tcp.) so that clients and browsers that support mDNS resolution can easily and automatically connect.
There is reset button that will allow you to revert to the default credentials if you have changed them.
This section shows all the associated clients on the internal private wireless connection. Both the MAC address and IP address are shown.
If a wireless client supports the CANServer Client Identification Protocol then other options may be available and displayed in this area.
An example is the Heated Steering Wheel Retrofit board. It associates with the CANServer using the identification protocol which then causes the CANServer to display a configuration icon that can be used to access it's internal config.
Further details on the identification protocol can be found: here
The External Wireless Connection section allows you to configure multiple external wireless networks that the CANServer will attempt to connect to. (You could configure home and work as an example).
When one of these networks is found the CANServer will attempt to connect to it and obtain an IP address via DHCP. The status of the external wireless interface will be shown in the status column along with any obtained IP address.
You can delete an previously added connection by using the delete button associated with the SSID you wish to delete.
If you wish to change the password of an already configured SSID you will need to delete it and re-add it.
As of firmware version 2.1 the CANServer can also call a webhook url when a connection is established to a configured SSID.
This webhook call can be used to notify an external service of the presence of a CANServer on the network. And example use-case is that log files can then be automatically downloaded when the CANServer has connected to a network.
The webhook will be a HTTP POST to the provided URL. The payload of that POST has the following details:
User-Agent: CANServer
Content-Type: application/json
{
"IP":"172.20.20.55",
"Name":"CANServer-DDesk"
}
The IP and Name parameters in the body are populated based on the obtained IP address and the configured Hostname.
The Panda Connection section allows a tweak to the frequency that the CANServer sends CAN frames out. If you are using a v1 compatible Panda client depending on the volume of CAN traffic the CANServer is processing it might overwhelm both the wireless network connection or the Panda client. In that even you can throttle the outgoing data by setting the Max Send Interval to a higher number.
The Max Send Interval will adjust how often the CANServer sends a Bus ID/Frame ID combination out and is defined in milliseconds. The higher the number the less often the CANServer will send a specific combination.
As an example if the CANServer is receiving a CAN frame at a rate of 10Hz (so 10 times a second, or once every 100ms) the following results will occur based on the applied Max Send Interval.
| Max Send Interval | Panda Send Frequency |
|---|---|
| 0 | 10 frames/s* |
| 10 | 10 frames/s* |
| 100 | 10 frames/s* |
| 200 | 5 frames/s |
| 500 | 2 frames/s |
| 1000 | 1 frame/s |
*raw rate as the interval is less or equal to the the receive rate
This allows tuning of the connection details so as to achieve an acceptable update rate in the client, but limit the network traffic and processing requirements to as little as possible.
When using a Panda v2 protocol compatible client (such as tes•LAX) the interval can be left at 0 as the Panda v2 protocol supports filtering which results in drastically reduced network traffic.
Full details for the websocket support are detailed fully here