degrees C. Refer to the sensor data sheet for actual scaling information. If transmit period and hysteresis
are left as zero on this page, the gateway will send back whatever settings it got from the sensor for those
parameters, which would have been initially set using the sensor configuration utility (independent of
anything the BB2-7010-06 does).
Analog Input is the most suitable BACnet object for recording data values read by sensors. Analog Value
would also be an appropriate choice, although with no particular advantage over Analog Input. Analog
Output is not a suitable choice for sensor values since these objects are meant to be written to BB2-7010,
not read from. Analog Input is typically a sensor object, while Analog Output is typically an actuator
object.
Sensor alarm setpoints can be fixed values that are stored in the XML configuration file, or setpoints can
be provided dynamically by an external system. Sensor alarm setpoints can be taken from an Analog
Value object or Analog Output object. You would not use an Analog Input object for alarm setpoints since
you cannot write to an Analog Input. The notation "Input" means input from sensor hardware, or input to
the network. The notation "Output" means output to sensor hardware, as would be applicable for an alarm
setpoint. The Analog Value object can be used without any requirement for command priority; however, at
startup, the Analog Value present value properties in the BB2-7010 will all default to zero. If the BACnet
client (typically a facility management system) is not quick enough to write setpoints to the BB2-7010,
alarms will be cleared in the sensor the first time it reports in, and only restored at some later time when
the client gets around to updating the setpoints. If you want the BB2-7010 to use known default alarm
setpoint values at startup, use Analog Output objects for alarm setpoints, and enter the default alarm
setting as the "Relinquish Default" value.
If an alarm setpoint object is given, it will be used, and will override any setpoint value entered on this
page. If the setpoint object is left set to zero, then the setpoint value shown on this page will be used. All
parameters on this page are stored in the XML configuration file when you click Save on the Config File
page. (Forgetting to save the file will result in settings being lost the next time power is lost.) Whether a
setpoint object or setpoint value is provided, in either case, the Alarm Time must be non-zero to enable
the alarm.
The "alarm time" is the amount of time in sensor update periods (transmit periods) that the condition
must exist before being reported as an alarm. Alarm time of zero is disabled (on this setup page). A zero
will be transmitted as FF to the sensor, and all alarm time values offset by -1 when sent. This means
alarm time of zero disables the alarm, alarm time of one enables the alarm with immediate reporting, and
alarm time of two will delay the report by one sensor update period (shown as 300 seconds on the
example above).
Alarms are not particularly useful if the alarm state is not reported. The means for reporting alarms states
is via the status objects provided on the setup page. The most suitable object type is Binary Input,
although any Input or Value object could be used. The alarm state value will always be either zero or one,
and therefore Binary is a suitable type. Binary objects also have the option of associating user defined text
strings with the active and inactive states. Changes in alarm state can be reported autonomously with
BACnet COV subscriptions or SNMP traps. The alarm states can also be queried via Modbus.
16.3 Sensor Data Page
The screen illustrated below shows sensor data and additional diagnostic information. This page shows
sensor data as received most recently. The data received will be displayed here regardless of whether the
data has been assigned to any BACnet objects.
16. WiFi Sensor Setup - PointSix, AirTest
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