Mitsubishi Electric MELSEC iQ-R Series Programming Manual page 1282

■Tracking processing (1)
• Tracking processing is performed when all of the following conditions are satisfied.
• 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.
100
E2= ×(SPR-RMIN)
RMAX-RMIN
• 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.
■Variation rate limiter (2)
Variation rate limiter processing performs the following operations, and stores the result in the current ratio value (R
Condition
)  DR
(SPR-R
n
)  -DR
(SPR-R
n
|SPR-R |<DR
n
■Ratio calculation (3)
The ratio calculation is performed with the following operational expression.
R -RMIN
n
BW= ×E1+BIAS
RMAX-RMIN
■Loop stop processing (4)
The following processing is performed according to the SPA status of the alarm detection (ALM).
SPA status
1
0
■Control cycle determination (5)
If the specified control cycle is not reached, output value (BW) is set to 0 and the S.R instruction is terminated.
If the specified control cycle is reached, "mode determination (6)" is performed.
■Mode determination (6)
The following processing is performed depending on the control mode (MODE).
Control mode (MODE)
CAS, CCB, CSV
MAN, AUT, CMV, CMB, CAB, LCM, LCA, LCC
Operation error
Error code Description
(SD0)
3400H An invalid operation (such as division by zero) is performed.
3402H The value specified by (s1) or (d2) is a subnormal number or NaN (not a number).
3403H An overflow has occurred.
3405H The control cycle (CT) setting is less than 0.
The execution cycle (T) setting is less than 0.
The value divided the control cycle (CT) by the execution cycle (T) exceeds 32767.
11 PROCESS CONTROL INSTRUCTIONS
1280
11.3 Control Operation Instructions
Operational expression
R =R +DR
n n-1
R =R -DR
n n-1
R =SPR
n
Processing details
The loop stops. When the loop stops, the following operations are performed and the S.R instruction ends.
• The last output value (BW) is held.
• The control mode (MODE) is set to MAN.
The loop runs and "control cycle determination processing (5)" is performed.
Processing details
• If the set value (E2) is specified, engineering value transformation processing (refer to the following
expression) is performed, and then "variation rate limiter (2)" is performed.
SPR=
• If the set value (E2) is not specified, "variation rate limiter (2)" is performed without performing
engineering value transformation processing.
"Tracking processing (1)" is performed.
RMAX-RMIN
×E2+RMIN
100
).
n