Threshold
ON point
Time
Input V
alue
Input
Hysteresis
OFF point
Industrial,
Scientific, and
Medical Band
(ISM)
The ISM, or Industrial, Scientific, and Medical band, is the part of the radio spectrum that does not
require a license for use. The Sure Cross radios operate in the ISM band.
latency
A network's latency is the maximum delay between transmission and reception of a data signal.
lightning
arrestor
Also called a lightning suppressor, surge suppressor, or coaxial surge protection, lightning arrestors are
used in remote antenna installations to protect the radio equipment from damage resulting from a
lightning strike. Lightning arrestors are typically mounted close to the ground to minimize the grounding
distance.
line of sight
Line of sight is the unobstructed path between radio antennas.
link failures
A Host Link Failure occurs when the defined timeout period, typically about four seconds, elapses with
no communication between the host system (or Modbus master device) and the DX80 Gateway.
A Gateway Link Failure refers to the radio link between a Node and the Gateway and is determined by
three global parameters: Polling Interval, Maximum Missed Message Count, and Re-link Count. When
the Node’s Gateway Link Failure flag is set and the Gateway determines a timeout condition exists for a
Node, any outputs linked from the failing Node are set to the user-defined default state.
A Node Link Failure is determined by the polling interval or the out-of-sync timing. When a Node detects
a communications failure with the Gateway and the Node Link Failure flag is selected, the output points
are set to the user-defined states and the inputs are frozen.
local and non-
local registers
Local registers are registers specific to the device in question. When discussing a Gateway, the
Gateway's local registers include the registers specific to the Gateway in addition to all the Nodes'
registers that are stored in the Gateway. Non-local, or remote, registers refer to registers on other
Modbus slave devices, such as other MultiHop slave radios or third-party Modbus devices.
master/slave
relationship
The master/slave relationships is the model for a communication protocol between devices or
processes in which one device initiates commands (master) and other devices respond (slave). The Sure
Cross network is a master/slave network with the Gateway acting as the master device to the Nodes,
which are the slave devices. A PC can also be a master device to a wireless sensor network. See
star
networks
.
maximum bad
count
The maximum bad count refers to a user-established maximum count of consecutive failed polling
attempts before the Gateway considers the radio (RF) link to have failed.
maximum
misses
The maximum misses is the number of consecutive polling messages the Node fails to respond to. For
more information, see Polling Rate and Maximum Misses.
median filter
When the median filter is turned on, three samples are taken for each analog sensor reading. The high
and low values are discarded and the middle value is used as the analog value. Set to zero (0) to turn off
the median filter. Set to one (1) to turn on the median filter.
Sure Cross
®
Performance DX80 Wireless I/O Networks
62
www.bannerengineering.com - Tel: + 1 888 373 6767
