Understanding Radio Frequency Data Communication (RFDC)
How radio frequency data communication works, what it can do in your work environment, and what it can do for your bottom line.
An Introduction to Radio Frequency
Automated Data Collection, or ADC, began revolutionising business processes more than 25 years ago. Technological innovations since that time have brought the ultimate goal of flawless, immediately accessible data to reality. And, the continual search for better and faster technologies has brought about real-time, on-line information employing radio frequency (RF) as the conveyance.
What are Radio Frequency Waves?
Electromagnetic energy pervades the entire uni-verse, and radio frequency waves are part of the electromagnetic spectrum. These waves oscillate at a unique frequency which is expressed in cycles per second, or Hertz, and is analogous to the musical pitch of a plucked guitar string. Radio Frequency Data Communication (RFDC) uses RF waves as a medium for transmitting and receiving information. The RF waves used in data communication oscillate at approximately 400, 900, and 2400 million cycles per second. This places RF waves at or near the frequencies used in RF radio broadcasts, and they are impossible to detect except with an RF receiver. They are completely harmless at these levels.
Characteristics of RF Waves
RF waves possess two characteristics that are relevant to data collection:
- The ability to act as a conveyor of information. By passing electrical data through an RF transmitter, the signal can be converted to an RF signal and broadcast to an RF receiver almost anywhere in the vicinity. The receiver can then reconvert the RF signal into electrical data that can be used by other hardware such as a computer.
- The need to operate in relatively short ranges. As long as two RF transmitters are outside each other’s effective range, they can broadcast on the same frequency without interference.
Benefit from Customer or Regulatory Requirements
There are two applications for RF information management. One is RF Identification (RFID). RFID employs identification tags with microchips embedded in them. These chips emit signals that uniquely identify them. By affixing the chips to any article, it can be identified and tracked.
Although RFID is a major branch of RF information management, this document focuses on RFDC. The other typical application for automated data collection systems uses bar code labels, fixed or hand-held scanners, and a computer system.
Information is encoded in the bar code label which is affixed to the object to be tracked or counted. A bar code scanner is used to transmit the encoded information to a reader which converts it to a useable form.
What happens next depends on what kind of equipment is used:
- A hard-wired system transmits the information in real-time via wires and cables connecting the equipment to your computer.
- Portable readers without RF capability can be used to collect data, which is temporarily stored in the reader and periodically batch uploaded to the host computer.
In either case, a controller acts as a kind of switch-board between the data coming from the remote readers and the computer. RFDC expands upon these conventional configurations by replacing wires with RF signals. RFDC configurations typically consist of the following components:
- A controller connected to the host computer.
- A base station connected to the controller that transmits to end devices.
- An access point that acts as a bridge between the enterprise network and the radio system.
- An RF reader or an RF network gateway connecting a standard (non-RF) reader to the network.
- A transmitter integrated into each reader.
- When needed, a repeater to boost and re-transmit the signals.
Since there are no wires between the base station or access point and the readers, they are completely portable, yet the information collected is still available in real time. RFDC differs from conventional systems only in the medium used to upload information. This enables manufacturers and distributors to easily upgrade to RF without scrapping existing systems.