SmartSwarm 300 Series
:
81
Delta
✔
✔
Table 29. Delta Event
Note
: As explained in the Counter section, a counter is always increasing. A drop in value is assumed to indicate a
single roll-over event. Therefore, for an 8-bit counter (range 0 - 255), a change in value from 254 to 253 is an
increase of 255, not a decrease of 1.
Like the Change event, you can enter a “Change by” value after selecting the Delta event type on a register:
The MQTT publish will only be triggered if the enriched register value has changed by
greater than or equal to
this
value,
compared to the last time it was published.
The following example shows a register that ramps monotonically from 0, incrementing by 1 on each Modbus
master access. The red annotations show when MQTT publishes will be triggered, assuming that a Delta rule is
applied, with “Change by” = 9.