User`s manual

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MELSEC-Q
13 AUTO TUNING
In the upper/lower limiter, the following operation is performed and the result of the operation is
output to BB4 and BB5.
Result
Condition
BB4 BB5 BB16 MV
Processing after upper/lower
limiter
T1 MH 1 0 1
Original MV
unchanged
T1 ML 0 1 1
Original MV
unchanged
S. AT1 instruction is terminated.
ML T1 MH000T1
The processing in 2) and later is
performed.
2) The stepped manipulated value preset flag is turned to 1.
3) The counter from auto tuning start is cleared to 0.
4) The input value (E1) is stored into the auto tuning start-time PV0.
5) The input value (E1) is stored into the last process value (PV
n-1
).
6) The maximum slope value, maximum slope-time counter, maximum slope-time PV,
response speed (R) and equivalent dead time (L) are cleared to 0.
(b) If the stepped manipulated value preset flag is 1 "(8) Sampling cycle judgement
processing" is performed.
(8) Sampling cycle judgment processing
Whether the sampling cycle is reached or not is judged from the AT1 sampling cycle (AT1ST).
(a) If the sampling cycle is not reached, the S. AT1 instruction is terminated.
(b) If the sampling cycle is reached, "(9) Response waveform observation processing" is
performed.
(9) Response waveform observation processing
The following processing is performed for the input value (E1).
(a) Response waveform observation
1) The counter from auto tuning start is incremented.
2) The following processing is performed according to the input value (E1) and last process
value (PV
n-1
).
Reverse operation (PN 0)
Forward operation (PN 1)
T2
E1 PV
n-1
3) The input value (E1) is stored into the last process value (PV
n-1
).