MA-025
–
DGA 900 Operator Guide
–
Rev 2.0
12-Apr-19
Page 29 of 92
6.8
Alarms
Perception allows deadbands to be defined for each alarm. A deadband establishes
another limit for clearing the alarm and prevents an alarm returning to normal until the
alarm condition is cleared by the deadband. This reduces the number of false alarms and
the amount of chattering. For example, an alarm triggered at 200 ppm with a deadband of
3 will remain in the alarm state until the value falls below 197 ppm.
Note:
Deadbands are specified in the units being measured. Gases are specified in PPM,
temperature in degrees Celsius.
The host network must have the capability to transmit alarms and critical
messages during times of heavy use, including but not limited to network
storm conditions. If this requirement is not met or has not been tested, the
notification of hazardous gas levels could be delayed by a network slowdown.
6.8.1
Gases
Select
Alarms
>
Gases
to open the Gas Alarms Configuration page as shown in Figure
Figure 6-18: Gas Alarms Configuration
