Best Practices


#1

Hello,

I am looking to use the AWB3300-B (Anybus Wireless Bridge II) in an industrial environment. I want to use it as a cable replacement to talk between to Allen Bradley PLCs. Our goal is to pass some INTs and REALs between processors. We did some testing in both wifi and bluetooth. Wifi was giving us lots of communication losses and bluetooth was a lot more reliable. So we are set on bluetooth but it seems that the range for bluetooth isn’t as good as wifi. I read the Anybus whitepaper on “Wireless technologies for industrial communication” and the anybus manual.

With all that being said, I have some questions and hope to improve the performance of this wireless bridge.

  1. Are there any settings on the device’s webpage (192.168.1.99) that I can change to improve and optimize performance? Our application is 1 master and 2 slaves but normally only 1 slave will be active at a time. Constant connection is the priority, speed is secondary.
  2. How can materials effect my signal? Structural materials around these devices will be metal, concrete, and maybe a wood floor. Does wifi and bluetooth behave differently since they are at different frequencies?
  3. How can I optimize the mounting orientation of the anybus so the antennas are best utilized? We won’t be able to have the “face” of each unit pointing at each other all the time. Does wifi and bluetooth behave differently since they are at different frequencies? For example, what if both antenna’s point up to the ceiling or both pointing at the floor. How will that change the signal strength?

Thanks,

Linkm


#2

Hi @linkm,

Yes and no. While you can’t just turn up the power on the antenna, you can make configuration changes that are more conducive to your conditions. For example, 2.4 GHz will have better range, but 5 GHz will have greater speed. However, there is often much more traffic and interference on the 2.4GHz bands (which are also used by bluetooth!)

Any solid material and even invisible ones, like radiation, can affect the signal. While “line of sight” is ideal, it’s not always possible. Avoid putting the antenna in any time of enclosure. Thick concrete walls and metal have a much bigger impact on the signal than drywall or wood paneling. 2.4 GHz WiFi and bluetooth are similar and in the same range so they can interfere with each other.

The Wireless Bridge IIs do not have directional antennas so it’s best to mount them as high as possible in a room where there is the best line of sight to the target.

You could greatly increase performance if you can determine what kind of traffic is in the area. There are many free apps for Android and probably Apple too that will check all of the WiFi signals in the area so you can see where the traffic is. You can also get a free trial for Wi-Fi Scanner for Windows. There are a lot more available channels in the 5 GHz range (23 vs only 3 in 2.4 GHz) if you do not have to go a long distance (over 50 feet with a lot of obstacles or 100+ feet with a clear shot.) How far are these devices apart?

Kyle


#7

@linkm,

I will add that when mounted on a metal plate, the Wireless Bridge will act more like a directional antenna because the signal is reflected in one direction, so if all of the access points are in the same direction, you may be able to use this “trick” to get a stronger signal and better range.


#8

Hi Kyle,

I did not realize that Bluetooth and WiFi are on the same frequency. Our distance is probably right around 100 ft and 5GHZ may not work for us then.

We will try to mount the antennas as high as possible to remove obstacles in the way. However, due to the application, one of the radios will have to be mounted underneath a “lip” of a big metal frame to protect it.

If the application struggles with speed, we will try the 5GHz out. Unfortunately we don’t have easy access to the end customer’s facility.

Thanks,

Linkm


#9

Make sure the devices all have the latest firmware and I would highly recommend checking the surrounding wireless traffic.

This is one of the applications that I have used:


#10

Yes, and when you look at the wifi analyser you see which channels are used. Choose the channel that is most free of other channels. In 2.4 GHz choose between 1,6 or 11, at 5GHz you are free to choose. BT is also 2.4 GHz but uses frequency hopping and therefore it is much more stable but also have a lowe data throughput. Other appliances could also interfere with the signal like radio’s, microwave, PIR etc.