system
operating
margin (fade
margin)
The system operating margin, or fade margin, is the difference between the received signal level (in
dBm) and the receiver sensitivity (also in dBm) required for reliable reception. It is recommended that
the receiver sensitivity be more than 10 dBm less than the received signal level. For example, if the
signal is about –65 dB after traveling through the air and the radio receiver is rated for -85 dB, the
operating margin is 20 dB — an excellent margin.
tau filter
Set to zero (0) to turn off the tau filter. Set to 1 (weakest filter) through 6 (strongest filter) to turn on the
tau filter. (In the DX80 products, the Low Pass Filter is a combination of the median filter and the tau
filter.)
TCP/IP
TCP/IP stands for Transfer Control Protocol / Internet Protocol and describe several layers in the OSI
model that control the transfer and addressing of information.
time-division
multiple access
(TDMA)
TDMA is a wireless network communication architecture that provides a given slot of time for each
device on the network, providing a guaranteed opportunity for each device to transmit to the wireless
network master device.
thermistor
A thermistor is a temperature-sensitive resistor that changes resistance based on temperature
fluctuation.
thermocouple
A thermocouple is a temperature measuring device consisting of two dissimilar metals joined together so
that the difference in voltage can be measured. Voltage changes in proportion to temperature, therefore
the voltage difference indicates a temperature difference.
The different “types” of thermocouples use different metal pairs for accuracy over different temperature
ranges. Thermocouples are inexpensive, relatively interchangeable, have standard connectors, and
have a wide temperature range of operation. They can be susceptible to noise, with the wire length
affecting accuracy. Thermocouples are best suited for applications with large temperature ranges, not
for measuring small temperature changes over small ranges.
threshold and
hysteresis
Threshold and hysteresis work together to establish the ON and OFF points of an analog input. The
threshold defines a trigger point or reporting threshold (ON point) for a sensor input. When the input
value is higher than the threshold, the input is ON. Hysteresis defines how far below the threshold the
analog input is required to be before the input is considered OFF. A typical hysteresis value is 10% to
20% of the unit’s range.
Threshold
ON point
Time
Input V
alue
Input
Hysteresis
OFF point
In the example shown, the input is considered on at 15 mA. To consider the input off at 13 mA, set the
hysteresis to 2 mA. The input will be considered off when the value is 2 mA less than the threshold.
Setting threshold and hysteresis points prevents inputs from oscillating between ‘on’ and ‘off’ when the
input remains close to the threshold point.
timeout interval
The Timeout Interval is the total elapsed time before the system flags an error condition. This is a
calculated value from Polling Interval (sec) × Maximum Misses.
topology
Topology is the pattern of interconnection between devices in a communication network. Some
examples include point to point, bus, ring, tree, mesh, and star configurations.
transceiver
A transceiver includes both a transmitter and receiver in one housing and shares circuitry; abbreviated
as RxTx.
wireless sensor
network (WSN)
A wireless sensor network is a network of low-power electronic devices that combine sensing and
processing ability. The devices use radio waves to communicate to a gateway device, connecting
remote areas to the central control process.
Yagi
Yagi is the name commonly given to directional antennas. The full name of the antenna is a Yagi-Uda
antenna, named for the developers Shintaro Uda and Hidetsugu Yagi, both of Tohoku Imperial
University in Sendai, Japan. Yagi antennas may also be called beam antennas or directional antennas.
Sure Cross
®
DXM150 and 1500-Bx Wireless Controllers
www.bannerengineering.com - Tel: + 1 888 373 6767
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