In this document I will show the different methods available for connecting one or more BlackBirds to a single computer. I will also investigate issues related to disturbance and unexpected delays when using multiple BlackBirds.
Writer: Lars-Göran Fredriksson, Field Application Engineer, Kvaser AB
Version: V1.01 2019
Kvaser BlackBird v2 is a high performance wireless (WLAN) communication link for the CAN bus. The BlackBird v2’s ability to leverage existing wireless infrastructure makes it ideal for replacing cumbersome cable, accessing hard-to-reach CAN networks, or for monitoring a CANbus while in motion.
You can read more about the Kvaser BlackBird v2 on our homepage.
Before you try to use your BlackBird, download the two documents:
Questions I am often asked include:
Some of the questions are easy to answer, but in some cases, the answer is not so obvious. In many cases, you do not need an access point, you can connect the BlackBird directly to your computer. And if you have many BlackBirds running at the same time, yes, there will be some interference between the units. If they share the same resources (e.g. the same WiFi channel), they cannot transfer information at the same time but need to wait until the channel is free. Also, if they are too close to each other, the RF signals can cause blackouts in the receivers.
There are different ways to connect your BlackBird/s, with different results to be expected:
This is most probably the most common method of using the BlackBird.
When I use my BlackBird in this way, I get a typical transfer delay of 1.2ms. If we compare this with a Kvaser Leaf Light v2 (USB connected), then we find out that the BlackBird adds apps 0.8ms in transfer delay. (Kvaser Leaf Light needs appr 0.4ms to send one CAN message).
If I use two BlackBirds at the same time, then transfer delay is almost the same, sometimes 0.1ms longer.
Do they disturb each other? When I test the interfaces, I cannot say that they disturb each other. I am prepared to say that other traffic on the WLAN net causes more problems (my colleagues’ iPhones and some laptops use the WLAN).
This facilitates a direct connection between theBlackBird and the computer via aWiFi adapter. There is no need need for a router or physical access point.
It is possible to connect more than one BlackBird at the same time, but be careful, the SoftAP available in Windows is not as fast as an external WLAN AP.
When I use one BlackBird, I get a delay of appr 2ms. When using two BlackBirds at the same time, I get a delay in the region of 2.5ms. (Please note that the variance is quite high, approximately ±1ms).This is most probably caused by the SoftAP. In a comment from Microsoft, we can read: ”… this SoftAP is not designed to replace hardware-based wireless AP devices.”In many applications when you just want to listen to many CAN networks, this delay will probably not cause any problems.
Before we can connect multiple BlackBirds, we must learn how to connect one.
I will show how to do this in section2: “Connecting a single BlackBird”
By using a WLAN Access Point (AP), the BlackBird can communicate with any computer inside the AP’s visibility.
The computer can be connected to the LAN either via a physical LAN (Ethernet) cable, or via the wireless WLAN (Wi-Fi).
There are four major steps that you must perform:
We can now see that the BlackBird is on CANlib channel 0 and has the serial number 10541. Yes, that is my interface!
If we right click on “Kvaser BlackBird v2”, we will find two very important commands:
In this section, we will use “Configure Remote Settings”, and in the next section we will use “Pair via Wi-Fi”.
Select “Configure Remote Settings”.
Now we must follow some very important steps:
In the tab “Configuration”, you will find a button:”Browse Networks”. If we select that button, this dialog box appears:
Select “your” network from the list; I will select the Kvaser network.
What happens now? This SSID field has been filled in for us. (if appropriate, edit the ‘Geographical Region.)
In the tab “Security”, you will find a button:”Passphrase”. If we press that button, we can see this dialog:
Add a passphrase*, and press OK.
* Now we need some basic information on how the AP is setup. The most common setup today (2019-10-03) is the WPA2-PSK mode. Please check with your IT department as to how your AP is setup.
This has filled in a WPA2 key for us.
In the tab “Network” we can see an edibox named “Device Name”, let us change the name of the interface to something we can remember (instead of “Kvaser Remote #10541”).
I select the name “BlackBird_Helge_1”.
We are now ready to press the magic button “APPLY”, but before we do that, (no problem if you have already done it), select the tab “Status”.
Press “APPLY”
If we wait a few seconds, we hopefully can see the following dialog box, showing that the interface managed to connect the BlackBird to the AP:
I have selected the word BIND for this procedure. In the “Network Device Selector” it says “Connect”. The purpose with this step is to BIND a resource (in this case our beautiful BlackBird) to a channel on a specific computer.
Before we can use the BlackBird, let us disconnect the USB and connect the BlackBird to a powered CAN network. The BlackBird must be powered via the DSUB9 connector to be able function properly (via WLAN).
If you don’t have a powered CAN network, you can use the Kvaser T-Cannector v2 or the Kvaser DB9-Power Inlet.
When we open the Kvaser Device Guide, we can see that the BlackBird has disappeared from the list (we disconnected the USB, and powered it via the DSUB-9 connector).
Select MENU/TOOLS/Network Device Selector
If we are lucky, we can now see that our computer has detected the BlackBird.
Select the BlackBird and press the button “Connect”.
Now, the tool will BIND the selected BlackBird to our computer and the Kvaser Drivers for Windows will attach it to a CAN channel.
Something happens, “Service: State=6 (CONNECTION UP)” … it seems to work.
We can now see that we have a new interface attached to CANlib Channel 0, via the Wi-Fi network.
There are three methods of connecting a BlackBird directly to a laptop (computer with WLAN network).
All have the same key functions:
Wireless Ad Hoc is no longer supported by Microsoft (2019-10-01) and so I will not show how to use it.
In the Kvaser Device Guide, we can select “Pair via Wi-Fi”
This will startup a guide that helps you to connect your BlackBird directly to your laptop using “Wi-Fi Direct”.
Please note, there is an unwanted feature in how Windows handles the Wi-Fi Direct feature. If your WLAN card is connected to a 5Ghz network, it will open a 5GHz Wi-Fi Direct Soft AP. The BlackBird can only handle 2.4 GHz networks. Make sure that your WLAN card is in disconnected state or connected to a 2.4 GHz network.
This tool helps us to setup the Wi-Fi Direct connection.
If we do not need any special settings, then we just select “Pair Device and PC”.
The tool does 5 important things:
There might be situations when we not can use Wi-Fi Direct. One of my laptops does not support Wi-Fi Direct, but it does support VHN.
To use VHN, we must use the classical “Command Prompt”.
We will use the command: “netsh wlan”
For more information regarding NETSH, please read:
Netsh Commands for Wireless Local Area Network (WLAN) in Windows Server 2008
We will try to:
Command: netsh wlan show drivers
Response:
Interface name: Wi-Fi
Driver : DW1520 Wireless-N Half-Mini Card
Vendor : Broadcom
...
...
Hosted network supported : Yes
...
...Please note the line “Hosted network supported : Yes”. This line indicates that my interface supports WHN.
We enable the WHN soft AP by setting three parameters:
We can run three commands:
NETSH WLAN SET HOSTEDNETWORK MODE=ALLOW
NETSH WLAN SET HOSTEDNETWORK SSID=MyHostedNetwork
NETSH WLAN SET HOSTEDNETWORK KEY=My1SecretKey!Or, we can combine them into one command:
NETSH WLAN SET HOSTEDNETWORK MODE=ALLOW SSID=MyHostedNetwork KEY=My1SecretKey!Example
C:\WINDOWS\system32>NETSH WLAN SET HOSTEDNETWORK MODE=ALLOW
The hosted network mode has been set to allow.
C:\WINDOWS\system32>NETSH WLAN SET HOSTEDNETWORK SSID=MyHostedNetwork
The SSID of the hosted network has been successfully changed.
C:\WINDOWS\system32>NETSH WLAN SET HOSTEDNETWORK KEY=My1SecretKey!
The user key passphrase of the hosted network has been successfully changed.
OR
C:\WINDOWS\system32>NETSH WLAN SET HOSTEDNETWORK MODE=ALLOW SSID=MyHostedNetwork KEY=My1SecretKey!
The hosted network mode has been set to allow.
The SSID of the hosted network has been successfully changed.
The user key passphrase of the hosted network has been successfully changed.
Now we have ENABLED the WHN soft AP.
Our computer will now provide a wireless network named “MyHostedNetwork”.
To connect to the WHN, we must start it.
netsh wlan start hostednetwork Start the wireless Hosted Network.
(netsh wlan stop hostednetwork Stop the wireless Hosted Network.)
C:\WINDOWS\system32>netsh wlan start hostednetwork
The hosted network started.We have created a WLAN named “MyHostedNetwork” and started it.
It is now possible to connect one or more BlackBirds using Infrastructure mode described in section “2 Connecting single BlackBirds, Infrastructure mode”.
It is possible to connect multiple BlackBirds to one computer in all the different modes.
In infrastructure mode and WHN mode, just add as many BlackBirds as you like, following the instructions in section “2 Connecting single BlackBirds, Infrastructure mode”.
When using WiFi Direct mode, then we need to do some tweaking when setting up the WiFi Direct AP.
(Please note, the passphrase must fulfill the security policy of your computer)
Start the Kvaser Wi-Fi Pairing Tool
Now we must save the settings, as we will need them later.
Save the settings…
We can now start the tool:”Advanced/Configure PC Only”.
After one minute, it will time out and say that it failed to find a BlackBird. This is totally correct, because we have not yet configured the BlackBird.
But, most important, we can see that it has started the SoftAP.
What happened? Well, the tool removed all earlier SoftAP and started a new SoftAP with the name “MyWiFiDirectAP” and the Passphrase “!1Qaz2wsx3edc” (I happened to use that passphrase, now you know one of my most secret passwords☺)
We now have a Wi-Fi Direct SoftAP with the following parameters:
We also have an INI file named “MyBBGuideSettings.ini”
[Config]
Version=1
SSID=KV-WiFiDirect-LAGUR
Passphrase=337A33736E6E4A62B7C6624A3BEF6BD892F1065BC5
Region=1
Deviceaccess=1
Configprot=0
ForceHostedNet=0Start the Kvaser Wi-Fi Pairing Tool, open then INI file with “File/Open Configuration”, then start the tool “Advanced/Configure Device Only”.
It seems to be working!
You can repeat this step with all your BlackBirds.
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