ControlByWeb XW-110 User Manual page 7

XW-110™ WiFi Temperature Sensor Users Manual
Extending Temperature Sensors
Many factors can determine the maximum length of the cable, including the sensor network topology,
the type of cable used, the number of sensors and ambient electromagnetic noise.
Multiple sensors can be connected to the XW-110 Plus in two ways: directly connected (star topology) or
"daisy chained" (linear topology), shown below.
Combined cable lengths to all sensors of 50 ft using Cat 5e cable have been successful; however, due
to the uniqueness of installation environments, results may vary. Please test in the desired environment
before making a permanent installation.
The following are general recommendations that will maximize sensor runs and minimize problems:
• Use small gauge 3-conductor wire (Cat 5e, 18-3 thermostat wire, etc).
• Cat6 wire can be used, but Cat 5 and Cat 5e network cable is recommended, and has proven to
be an effective and low-cost solution for long runs. Cat 5e is more tolerant of different wiring
configurations.
•
Non-shielded works best for longer runs (shielding limits run length).
• The 1-Wire bus is "single-ended" and has no intrinsic noise protection. It is susceptible to
interference if the cable is routed near power lines, fluorescent fixtures, motors or other noise
sources. Keep the cable wiring short and avoid routing it near other electrical equipment.
The illustration below shows the recommended connection using Cat 5 network cable. Connect all
unused conductors to ground on the XW-110 or XW-110 Plus.
A linear (daisy chain) topology will minimize signal reflections, providing a more reliable connection and
will allow longer cable length than a star topology.
Daisy chain up to 3 temperature sensors to the XW-110 Plus using a Cat 5e network cable.
Xytronix Research & Design, Inc.
(The XW-110 supports only 1 temperature sensor.)
Installation and Setup
Page 7