Programming instructions

Designer’s Guide 53
Calsense
• A Calsense Local Radio Hub
• A radio survey conducted by Calsense prior to installing any local radio equipment:
This service is provided free-of-charge and must be requested by the designer. This helps
ensure adequate coverage at the proposed controller locations and determine the ideal
location for the Local Radio Hub to be installed.
• A Federal Communications Commission (FCC) license to operate the local radio system:
Upon completion of a radio survey, Calsense prepares all required FCC paperwork. Although
this service is free-of-charge, there is a one-time fee that must be paid to the FCC to license
the frequency. A nominal renewal fee follows this every two years to maintain the license.
• Final FCC approval completed prior to any local radio equipment being ordered.
Radio Range
The hub radio should have an LR-STICK (omnidirectional) or LR-YAGI (directional) antenna attached to a
pole or roof of a nearby structure. The controller can have an LR-DOME, LR-STICK, or LR-YAGI antenna.
Unobstructed range (line of sight visibility) of a system with dome antennas is between one and two
miles. Up to three miles can be obtained with LR-YAGI antennas. Tall trees, valleys, buildings, and hills
can severely attenuate the signal. A radio site survey will need to be done by Calsense to verify complete
coverage and for antenna recommendations.
Caution: Before committing a project to Local Radio, the designer should contact Calsense to test and
verify signal strengths at site locations.
FCC Licensing
Customers must obtain an FCC license to operate the Local Radio system. Frequency coordination
(selection) is handled through the Personal Communications Industry Association (PCIA) - [phone]
- and an application is submitted to the FCC. It is not difficult to obtain a license. There is a PCIA fee and
FCC license fee that must be paid as well.
Spread Spectrum Radio (model -SR)
The Calsense Spread Spectrum Radio communication option (model -SR) enables two or more controllers
to communicate using spread spectrum radios. A spread spectrum radio is a 1 watt radio modem that
uses the 902-928 MHz ISM (Industrial, Scientific, and Medical) band. Figure 28
shows an example of two
controllers communicating using spread spectrum radio.
This option also enables a computer running the Calsense Command Center software to communicate
with a controller through a spread spectrum radio System. A spread spectrum radio system has a single
spread spectrum radio Hub and one or more controllers in the field with the -SR option. The hub
manages data flow between the central computer and surrounding controllers.
Benefits of choosing the Spread Spectrum Radio communication option include:
• Does not require any trenching or wires
• Does not require FCC licensing
• Multiple controllers can share a single central communication device