Chapter 3-Preparing For Wireless Communications; Wrs Limits; Rsx Location - Siemens Wireless Room Sensor Solution User Manual

APOGEE Wireless User Guide
• Not Readily Available RF Radio – The WRS solution uses an IEEE 802.15.4 radio. These radios
are not readily commercially available. Therefore, there are limited sources to be able to procure a
radio to use for malicious purposes.
• Short Range – Typically, you need to be inside the facility to be within RF communications range of
a WRS/RSX wireless link.
For these reasons, it would be more difficult to hack into a WRS/RSX wireless link than a hard-wired
network (where someone can fairly easily "tap" into the hard-wired trunk).
Chapter 3–Preparing for Wireless Communications

WRS Limits

The following limits apply to wireless link and automatic channel changing operation.
• Wireless link limits:
– If the results of a CHECK RSX or BIND command at the WRS HMI shows that the WRS/RSX
pair has a Link Quality value of less than 90%, then the RSX and/or WRS should be
repositioned so that a better wireless communication link exists between them.
• Automatic channel changing—see Appendix D– Wireless Channels for details on limits.

RSX Location

The RSX should be typically mounted within 100 feet from its associated WRS. Where possible, mount
RSXs so the antennas are not blocked by metal objects or other obstructions that may hinder the signal
transmission (see Figure 6). Direct mount antennas allow the most flexible placement of RSXs for optimal
communications.
CAUTION:
Antennas must be at least 24 inches (61 cm) apart to avoid wireless interference
between two RSXs.
CAUTION:
To avoid interference, install the RSX at least 10 feet (3.1m) away from any wireless
ethernet (802.11) access point device.
14 Revision Date: July 10, 2008
Siemens Building Technologies, Inc.