ControlByWeb WEBRelay-10+ User Manual page 14

WebRelay-10 Plus™ Users Manual
Figure 2.2g - Direct Connection (Star) and Daisy Chain Connection (Linear)
Many factors will determine the maximum length of cable used to connect sensors to WebRelay-10 Plus™.
Some of these factors include, but are not limited to, the type of cable used, the number of sensors, ambient
electromagnetic noise, and sensor network topology. Combined cable lengths to all sensors of 600 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 permanent installation.
The following are general recommendations that will maximize sensor runs and minimize problems.
Cat 5 and Cat 5e network cable has proven to be an effective and low-cost solution for long runs. Other cable
types can be used, but cable capacitance may limit the length. Figure 2.2h shows the recommended connection
using Cat 5 network cable.
Figure 2.2h - Recommended connection using Cat 5 cable
A linear (daisy chain) rather than a star (direct connection) topology will minimize signal reflections. Appropriate
strain relief should be used at the WebRelay-10 Plus™ and other connections that may be subjected to vibration,
movement, or repeated handling.
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.
Protect any electrical connections with appropriate weather shielding.
Due to the broad range of applications and environments were the WebRelay-10 Plus™ may be employed,
installation success on long sensor runs may vary significantly.
Xytronix Research & Design, Inc. Page 14