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11 PROCESS CONTROL INSTRUCTIONS
11.3 Control Operation Instructions
■Tracking processing (2)
The set value (SV) is inversely transformed from the engineering value and SVn' is calculated (refer to the following
expression).
Tracking processing is performed when all of the following conditions are satisfied.
• If the set value (E2) is the upper loop MV, the TRKF of the disable alarm detection (INH) of the upper loop is set to 1.
■MV correction (3)
The instruction calculates the deviation (DV) based on the input value (E1) and the set value (SVn') after tracking, and then
calculates the MV correction value (MV').
• The deviation (DV) is calculated under the following conditions.
• The MV correction value (MV') is calculated under the following conditions.
■MV output (4)
The manipulated value (MV (BW)) is calculated under the following conditions.
■Three-position (on/off) control (5)
The BB operation results (BB1, BB2) are output under the following conditions.
■Loop stop processing (6)
The following processing is performed according to the SPA status of the alarm detection (ALM).
• The tracking bit (TRK) is set to 1.
• The set value (E2) is used.
• The control mode (MODE) is set to any of the following: MAN, AUT, CMV, CMB, CAB, LCM, LCA, or LCC.
E2 = SV
n
'
Condition DV
Direct action (PN = 1) E1 - SV
n
'
Reserve action (PN = 0) SV
n
' - E1
Condition MV'
DV(HS1+HS0) 100%
DV-(HS1+HS0) 0%
(-HS1+HS0)<DV<(HS1-HS0) 50%
Others Last value (BW value)
Condition BW
CMV, MAN, CMB, LCM BW=MV
n
CSV, CCB, CAB, CAS, AUT, LCC, LCA BW=MV'
MV
n
=BW
Condition BB1 BB2
BW75% 1 0
25% BW<75% 0 0
BW<25% 0 1
SPA status Processing details
1 The loop stops. When the loop stops, the following operations are performed and the S.ONF3 instruction ends.
• The output value (BW) is held.
• The control mode (MODE) is set to MAN.
• The output result (BB1, BB2) values are set to 0.
0 The loop runs and "control cycle determination processing (7)" is performed.
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