Kvaser BlackBird v2 vs Kvaser Air Bridge Light HS

Which one should I choose?

In some situations, either in the lab or in the field, you need to move and still connect to a CAN bus. Sometimes, you need to access a bus that is far enough away that expanding the CAN bus to your location would change bus behavior or be too far for the desired CAN bit rate. In these cases, having the CAN bus cable run to your PC location will not work. If you are using a crane and you need to monitor a CAN bus at the end of the arm, a wired system would be cumbersome. If you need to monitor a CAN bus on the move, such as in a moving automobile, a wired system will not work at all. In cases like these, what options do you have?

Within the Kvaser device catalog you have two options: the Kvaser BlackBird v2 and the Kvaser Air Bridge Light HS. Both devices allow for freedom of movement and a longer connection distance, but there are many differences between the Kvaser Air Bridge Light HS and the Kvaser BlackBird v2.

Let’s take a look at the devices themselves:

Kvaser BlackBird v2 (BlackBird)
The Kvaser BlackBird is a WiFi CAN interface. The Kvaser BlackBird v2 connects to your intranet and is treated like a device on the network, much like a network printer. The Kvaser BlackBird’s range is restricted to that of the WiFi network and closest WiFi router.

The BlackBird is an interface itself, much like a Leaf v3. The BlackBird has drivers available for Windows and now has drivers available for Linux. In Windows, using the Remote Device Configuration tool, you can configure the BlackBird to your WiFi network. Once the BlackBird has been configured, the BlackBird can be selected for use with the Network Device Selector. This connects the PC to the BlackBird and locks the unit for exclusive use with the PC (this is to prevent issues with conflicting messages being sent from the same interface). At this point, the BlackBird is available for use by the PC like any other Kvaser interface. You only need one Kvaser BlackBird connected to the CAN bus to communicate. You do not need another interface on the other end connected to your PC. You do not need another interface on the other end connected to your PC.

In Linux, a few more steps need to be taken. Currently, the Linux drivers and API files are in Beta testing and can be distributed by request. Along with the drivers, there is also a tutorial that can be used to help set up the device. At this time there is no Linux equivalent for the Remote Device Configuration tool and Network Device Selector. You will need to update the mhydrard.conf file and restart the remote service. Information on how to do this is available with the Linux drivers for the BlackBird.

Here is an example of what the mhydrad.conf file looks like and how it should be filled out:

Another method to connect the BlackBird in Linux is to utilize the REST API. SocketCAN is not supported.

The Kvaser BlackBird is capable of 15,000 messages per second and bitrates between 40-1000 kbps with support for Silent Mode. The Kvaser BlackBird uses WiFi standard 802.11 b/g/n and 2.4 GHz bandwidth to communicate with the WiFi network. However, CAN FD is not available.

Kvaser Air Bridge Light HS: (Air Bridge Light HS)
The Kvaser Air Bridge Light HS is a point-to-point, 2.4 GHz RF CAN bridge. Using an RF signal, the Air Bridge Light HS can connect two parts of a CAN network over a distance, with no cables needed. An Air Bridge Light HS comes with two units that are already paired with each other. You do not have to configure the two units to communicate with each other. The Air Bridge Light HS will also autobaud, meaning there isn’t a need to configure the bitrate, either. The Kvaser Air Bridge Light HS operates on the 2.4 GHz ISM band, with an estimated operating distance of 70m (depending on installation and environment). The antenna for both units are omnidirectional.

The Kvaser Air Bridge Light HS does have some limitations. Since Kvaser Air Gridge is a bridge, you will still need an interface to read CAN data. Typically, one Air Bridge Light HS unit will plug into the CAN bus and be powered by the CAN bus. The other unit will plug into a powered connection on the CAN interface (this powered connection can be provided by the CAN interface or some other power injector), which is in turn connected to a PC. This will create the RF connection between the CAN bus and PC.

Like the Kvaser BlackBird v2, the Kvaser Air Bridge Light HS does have some limitations. CAN FD is not available . and is limited to approximately 1200 messages per second transmission in both directions. The Kvaser Air Bridge Light HS does not buffer messages to be sent. This means that if the connection is lost, those messages are lost. The Air Bridge Light HS does try to re-establish connection automatically, however.

When and how should the Kvaser Air Bridge Light HS or Kvaser BlackBird v2 be used?

Both are a form of a “wireless” device. If there is a situation where the CAN bus will move, a cable gets in the way, a cable cannot be attached, or the distance between the PC and CAN bus varies or changes regularly, then the Kvaser Air Bridge Light HS or Kvaser BlackBird will be a good choice.

The Kvaser BlackBird v2 is the better choice if you need to access the CAN bus and there is something in the way. Since the BlackBird uses the local Ethernet, the BlackBird can cross walls or even buildings with messages being sent over the intranet. There is still the flexibility of movement as long as you are within range of a router.

The Kvaser Air Bridge Light HS is the better choice if a WiFi network is not available or if you just need a connection between two CAN networks. The Kvaser Air Bridge Light HS has the advantage of not needing any setup. If you also do not need to interface with the CAN bus, and just need to extend the CAN bus so different nodes can communicate at a longer distance, then the Air Bridge Light HS is the better choice.

Summary:

Kvaser BlackBird v2:

• CAN Interface
• WiFi connection between CAN bus and a PC.
• Needs to be configured to the network and connected through Kvaser Device Guide in order to access the device.
• Cannot be used with WiFi in LinuxCAN or SocketCAN.
• Can be used with the REST API, but this is a slower API.

Kvaser Air Bridge Light HS:

• CAN Bridge used to connect two CAN Bus segments
• No configuration. Will Auto Baud the bitrate
• Omni-Directional RF connection
• Does not have a need for drivers as the Air Bridge Light HS is not an interface that can connect to a PC.