Mitsubishi Electric MELSEC iQ-F Series User Manual page 27

■Reading
Internal memory
PriorityArray
Buffer memory
PresentValue
Update counter
Program
PresentValue
Update counter: The Ethernet module increments the counter every time a value is written to PriorityArray.
Range of the value: 01 to 655346553501 are repeatedly set.
(1) When the Ethernet module writes a value to the PriorityArray in the internal memory and calculates PresentValue, it updates the PresentValue in the buffer
memory, and increments the update counter.
(2) After the update counter has changed, the program reads the PresentValue in the buffer memory.
(3) Even when the value of PresentValue or the content of PriorityArray does not change, the Ethernet module increments the update counter when a value is
written to PriorityArray.
Therefore, it can be detected that there has been an update.
(4) Even when the program reads the PresentValue in the buffer memory at any timing, the value is the latest value.
Idx Value
1 Null
8 1
16 3
Default 0 Default
PresentValue = 1 PresentValue = 2
1
(1)
100
(2)
2
When PresentValue is
not changed
Idx Value
1 Null
8 2
16 3
0
2
101
Idx Value
1 Null
8 2
16 Null
Default 0
PresentValue = 2
-
(3)
102
(4)
2
4 FUNCTIONS
4.2 BACnet Object Function
4
2
25