Model CXT-IR
CXT-IR Instruction Manual
Rev. 2.1
Page 5 of 48
1.3
CXT Wireless Network
The CXT-IR sensor utilizes a transceiver radio, based on the IEEE 802.15.4 standard. The transceiver operates
at 2.4 GHz using DSSS encoding for robustness. DSSS was initially used by the military to resist jamming but
later was widely adopted for wireless implementations since it was robust in noisy environments. DSSS
transmits data across a wider frequency range than the actual frequency range required for the information. This
operation minimizes cross talk and interference from other transceivers and is less susceptible to noise from
other sources.
The IEEE 802.15.4 defines 16 separate RF Channels that can be used in the 2.4 GHz range. The default channel
is 1 but can be changed if there is RF interference or if there is an existing network using that channel.
Transceivers will only respond to other transceivers with the same RF Channel.
NOTE
If there are multiple CXT-IR networks in the same vicinity, each system must reside on a
different RF Channel to keep data from one appearing on the other system.
The 802.15.4 standard also implements a mesh network allowing any CXT-IR transceiver to relay or repeat data
between adjacent neighbors. This makes the network very robust and provides the following immediate benefits.
•
Allows re-routing of data in case of loss of a transceiver
•
Allows re-routing around wireless obstacles
•
Longer distances between transceivers because data can “hop” from one transceiver to the next
•
Included in sensor, controller and alarm station transceivers
•
CXT-IR transceivers can be deployed with less concern about physical location.
1.4
Battery Pack Options
The CXT-IR can be powered by a battery pack that enables the IR to be remotely mounted without the need for
external cabling. Detcon offers several battery pack options that are factory installed. Contact Detcon for more
information on these options.
1.4.1
Detconꞌs Smart Battery Pack
The Detcon’s plug-in Smart Battery Packs provides an output of 12VDC (See Figure 7). There are two versions
of the Smart Battery Pack. The first one is the 12V 2200mAh battery Pack (Detcon’s part number 976-0BP303-
120) and the second is the 12V 2900mAh Battery Pack. The CXT-DM monitors the battery pack for remaining
battery life.
The battery packs consists of rechargeable Lithium-Ion batteries and are equipped with integrated
safety electronics that include a fuel gauge, voltage monitor, and current and temperature monitoring circuits.
This “smart” circuitry continuously monitors the battery’s condition and reports critical status information to the
wireless transceiver via the Modbus™ registers. The battery packs are designed to plug into an 8-pin Beau
connector on the Terminal Board that the sensor is connected to. The battery Pack and Terminal Board are
housed in Detcon’s Aluminum Condulet to protect them from exposure to outside elements and still provide
Class I Div 1, C, and D approvals. Operating periods before recharge will vary based on sensor attached, but
can be as long as 3.5 months for the 12V 2200mAh battery pack, and 5 months for the 12V 2900mAh battery
pack before battery recharging is required. Improper use of the battery pack may be hazardous to personnel or
the environment and will void the warranty.
