Edge SoftwareDetails of Capabilities
The Deadband app is mainly used for filtering data. It subscribes to the value of the listenTopic key and applies deadband on the data as per the configuration. It then sends the data after the deadband has been applied to the publishTopic. The deadband configuration is on a per tag basis. The deadband type can be specified as either absolute or percent. The value can be any numeric value in the case of absolute deadband and should be less than 100 in the case of percent deadband. The timeout is specified in milliseconds.
For every tag received, the following deadband logic is applied.
Absolute Deadband
If the absolute difference between the current value of the tag and the last sent value of the tag is greater than the deadband value, the current value of the tag is sent. The current value and current time are stored as last sent value and last sent time respectively for use in the next comparison cycle. If the absolute difference is less than the deadband value, the current time is compared against the last sent time and if the difference is greater than the timeout, the current value of the tag is sent. Otherwise it is filtered.
Percent Deadband
If the absolute difference between the current value of the tag and the last sent value of the tag is greater than the deadband value percentage of last sent value, the current value of the tag is sent. The current value and current time are stored as last sent value and last sent time respectively for use in the next comparison cycle. If the absolute difference is less than the deadband value percentage of last sent value, the current time is compared against the last sent time and if the difference is greater than the timeout, the current value of the tag is sent. Otherwise it is filtered.