Mitsubishi Electric MELSEC iQ-R Series Programming Manual page 1399

Processing details
This instruction performs auto tuning to make initial setting of PID constants.
■Start signal determination processing
The instruction performs the following processing according to the auto tuning start signal (e1) and auto tuning completion
(BB16).
e1 BB16 Processing
0 0 • BB alarms from BB1 to identification alarm BB8 are set to 0.
• When the step manipulated value set completion flag is 1, the following processing is performed.
MV=MV-AT1STEPMV
• The S.AT1 instruction is terminated.
1 0 • "Loop stop processing" is performed.
0 1 • BB auto tuning completion (BB16) is set to 0.
• The S.AT1 instruction is terminated.
1 1 • The S.AT1 instruction is terminated.
■Loop stop processing
The following processing is performed according to the SPA status of the alarm detection (ALM).
SPA status Processing details
1 The loop stops. When the loop stops, the following operations are performed and the S.AT1 instruction ends.
• Auto tuning completion (BB16) is set to 1.
• When the step manipulated value set completion flag is 1, the following processing is performed.
MV=MV-AT1STEPMV
0 The loop runs, and "mode determination processing" is performed.
■Mode determination processing
The following processing is performed depending on the control mode (MODE) setting.
Control mode (MODE) setting
AUT, CAB, CAS, CCB, CSV, LCA, LCC
MAN, CMB, CMV, LCM
■Input check processing
The following processing is performed according to the alarm detection (ALM).
Alarm Detection (ALM)
PHA or HHA is 1.
PLA or LLA is 1.
■Timeout determination processing
This function determines whether the auto tuning processing has reached the AT1 timeout time (AT1TOUT1).
Auto tuning processing
If the AT1 timeout time (AT1TOUT1) is reached
If the AT1 timeout time (AT1TOUT1) has not been reached
Processing details
The following processing is performed and the S.AT1 instruction is terminated.
• The control mode alarm (BB7) is set to 1.
• Auto tuning completion (BB16) is set to 1.
• When the step manipulated value set completion flag is 1, the following processing is
performed.
MV=MV-AT1STEPMV
"Input check processing" is performed.
Processing details
The following processing is performed and the S.AT1 instruction is terminated.
• The input upper limit alarm (BB2) is set to 1.
• Auto tuning completion (BB16) is set to 1.
The following processing is performed and the S.AT1 instruction is terminated.
• The input upper limit alarm (BB3) is set to 1.
• Auto tuning completion (BB16) is set to 1.
Processing details
The following processing is performed and the S.AT1 instruction is terminated.
• The input upper limit alarm (BB6) is set to 1.
• Auto tuning completion (BB16) is set to 1.
"Timeout (after maximum ramp) determination processing" is performed.
11 PROCESS CONTROL INSTRUCTIONS
11.7 Auto Tuning
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