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Wireless / Radio comms with digital panel meters, large displays and message displays - a guide
It would be beneficial in many installations to use a wireless communication link between devices, to save on cabling costs or to allow greater freedom of movement.
Examples can include communicating between a load cell amplifier and a large display on a moving crane, or from a pallet counter to a display in a fork lift truck.
We have a number of handy solutions which suit the many different site conditions you might encounter.
This guide is intended to make you aware of some of the important things to consider when planning wireless systems, because a wireless link might be unsuitable for your application, and it is better to realise that before you design and install your system.
"Wireless systems cannot afford to be trivial, unless the application is trivial."
Wireless radio signals - their nature.Wireless modem devices usually operate in the UHF or Microwave radio bands and are limited by law in the amount of power they can radiate.
UHF and Microwave energy is similar to light in many respects...
Wireless links - are they for you?
Mobile phones and WiFi operate at similar frequencies to wireless modems and you will know from experience that signals can be frustratingly unreliable in certain places. The same is true for wireless modem signals - they are vulnerable and simply not as reliable as wired links, especially in a complex industrial environment.
Getting the best reliability out of wireless links
Now that we realise the limitations of wireless links, and we have chosen a suitable application which does not require total reliability, we can look at ways of getting the best reliability we can, in the environment it will be operating in.
Might you need to add other devices to your wireless network?If you want to expand your network and include other devices, they will all need to use the same communication protocol and transport layer. What will it cost to include the same wireless system in those devices, if they don't support it as standard? Is that actually possible?
Will you need a custom data-translator or gateway?
Can you extend your wireless network distance if you need to?Systems change. If you need to extend the distance between devices on your wireless network, or need to talk around a corner or through a wall which wasn't there before, is that easy to do? Can you add additional routers in the signal path to extend it?
Do you need a license for your wireless network?If you have a challenging application, where high power is required in order to achieve reliable communication, you may need a license.
Are you relying on batteries to power your wireless device?If you lose your wireless link because the batteries have failed, will there always be someone on hand who will be able to diagnose that reason and change batteries fast? Will they be able to source the batteries quickly? Will your wireless device be easily accessible when the batteries need changing? Will the device need re-configuring if its batteries have failed? Does everyone know how to do that?
What happens if you can't get replacements in the future?When one of your wireless devices fails in the future, will you be able to get a drop-in replacement?
Will it use a protocol developed and supported by one manufacturer? Will that device still be in production? Will the manufacturer still have stock? Or will it be a generic protocol supported by many manufacturers, so alternative sourcing is possible?
Is data security important to you?If your data is important and you want to avoid it either being intercepted or maliciously corrupted (hacked) you should transport it over a secure transport layer.
Being wireless, the data is spread over a wide area, for anyone in range to intercept. Similarly, your receiver could be in the capture zone of signals sent from devices you have not authorised, or may not be aware of.
The de-facto means of achieving secure wireless links is via the https protocol on WiFi. We use this method in our cloud based applications between the clients and the server.
You cannot hope to achieve similar security between 'simple' devices, as appreciable computing power is needed to achieve the encryption and decryption.
If security is important, please contact us with your wireless requirements and we will be happy to help with a system which will give you the best possible reliability and security to suit your application's needs.
We may advise against a wireless link, if it would be unlikely to give the reliability or security you need...
In which case, we will offer alternative solutions.
Arranging the parts of your wireless system from beginning to end for best performance.
We will look at where the best places are for siting the components of a typical system...
The beginning of the link...
The end of the link...
The answers are not as simple as you might think and need careful thought and planning for each application. More soon...
We look forward to hearing from you!