1. OCS & wireless technology

2. Wireless Options Serial versus Ethernet interfaces
Serial-based radios typically replace relatively low-bandwidth RS-232 transmissions
A wireless radio (if properly installed) will provide a relatively reliable, low bandwidth connection
Serial based industrial hardware/software is generally fault tolerant
Ethernet-based radios typically replace high bandwidth 10/100MB transmissions
In many situations, a wireless radio will fail to deliver a reliable, high bandwidth connection
Much of the software that makes up an ethernet “stack” is many years old - and was written with wired connections in mind. It is often not fault tolerant enough for a wireless environment.

3. Wireless Options
Today, Horner recommends serial based wireless solutions
WiFi/ We do not have a WiFi option that we recommend. That doesn’t mean it doesn’t exist - but we haven’t looked for it.
900MHz 1W radio. This is the best solution for most applications in North America. It has the best range and fault tolerance.
2.4GHz 60mW radio. This is currently our lowest cost solution, and the best solution for Europe.
Cellular Radio. This is the best option in applications which are highly mobile, remotely located, or in areas of unsuitable terrain. It also provides a convenient messaging service (SMS).

4. Wireless Basics
Wireless systems have several components which must be examined
Transmitting Element - provides Power for data sent via RF waves
Receiving Device - receives the signal, which must be done with sensitivity & error rejection
Environment - will affect RF waves as they pass through, causing interference
Antenna - impacts the distribution and focusing of the signals

5. Wireless Basics Visual vs. RF Line-of-Sight & the Fresnel Zone
Visual LOS. The ability to see from one site to another. It requires only a linear path between two points
RF LOS. Requires not only Visual LOS, but a football shaped path free of obstacles - called a Fresnel Zone

6. Wireless Basics
Overcoming Obstructions by Raising Antenna Height

7. Wireless Basics Increasing the RF signal by Increasing Antenna Gain
Flashlight Analogy
Omnidirectional
Directional
Omni
Directional Yagi

8. Wireless Basics Summary of Ways to Maximize System Range
Use 900MHz Radio
Increase Transmitter (TX) Power
Regulated by the Government
Improve Receiver (RX) Sensitivity
Increase Antenna Gain
Use appropriate antenna
Use short antenna cable
Clear the Environment (Fresnel Zone) of Obstructions
Physical Obstructions (trees, walls, etc.)
RF Interference (wireless LANs, pagers, cell phones, etc.)