Difference Operation Function - Mitsubishi Electric MELSEC iQ-F FX5 User Manual

Difference operation function

The digital operation value at the start of this function is treated as 0 (reference value). Thereafter, values that increased or
decreased from the reference value are stored in the buffer memory.
Digital operation value
10000
7500
5000
2500
0
-2500
'CH1 Difference conversion
No request (0)
trigger' (Un\G470)
CH1 Digital operation value
before difference conversion
'CH1 Difference conversion
standard value' (Un\G432)
'CH1 Digital operation value'
(Un\G402)
'CH1 Difference conversion
Not converted (0)
status flag' (Un\G408)
Operation
The digital operation value at the start of the difference conversion (the data stored inside the analog input module before the
difference conversion starts) is determined as a difference conversion reference value. The value acquired by subtracting the
difference conversion reference value from the digital operation value is stored in 'CH1 Digital operation value' (Un\G402).
At the start of this function, the digital operation value is 0 (because the digital operation value and the difference conversion
reference value have the same value at the start).
• Digital operation value after difference conversion = Digital operation value - Difference conversion reference value
■Starting the difference conversion
1.
Change 'CH1 Difference conversion trigger' (Un\G470) from No request (0) to Trigger request (1).
The rise of No request (0)  Trigger request (1) is detected as a trigger. When the trigger is detected, the digital operation
value at the start is output to the difference conversion reference value. The value acquired by subtracting the difference
conversion reference value from the digital operation value is stored in 'CH1 Digital operation value' (Un\G402). After the
value is stored, 'CH1 Difference conversion status flag' (Un\G408) turns to Converting difference (1).
■Stopping the difference conversion
1.
Change 'CH1 Difference conversion trigger' (Un\G470) from Trigger request (1) to No request (0).
The fall of Trigger request (1) to No request (0) is detected as a trigger. When the trigger is detected, the difference conversion
stops, and 'CH1 Difference conversion status flag' (Un\G408) turns to Not converted (0). Thereafter, the digital operation value
is stored as it is in 'CH1 Digital operation value' (Un\G402).
Trigger request (1)
...
6000 7500 10000 10000
0 7500
...
6000 0 2500 2500
Converting difference (1)
'CH1 Digital operation value' (Un\G402)
No request (0)
...
7500 7500
...
7500 7500
Not converted (0)
Time
1 FX5-4AD
1.4 Functions
1
41