Mitsubishi Electric MELSEC iQ-R Series Programming Manual page 186

Setting data
■Input/output variable
Variable Description
name
PVP PV input (unit: %)
CASIN_T Cascade SV input (unit: %) (With tracking) (Indirect
address)
MVP MV output (unit: %)
■Public variable (operation constant)
Variable Description
name
TRK Tracking flag
SVPTN_B0 Setting value (SV) used
SVPTN_B1 Setting value (SV) pattern
*1 When 1 (tracking is executed) is set to the tracking flag, connect CASOUT_T of the primary loop with the input variable CASIN_T.
■Tag data
For details on tag data that is read or written with this tag access FB, refer to the following.
Page 523 R
Processing details
■Engineering value conversion
This function block performs engineering value conversion processing.
RMAX-RMIN
SPR= ×CASIN+RMIN
100
SPR: Setting value (%)
RMIN: Ratio low limit (%)
RMAX: Ratio high limit (%)
CASIN: Setting value (%) from primary loop
■Variation rate limiter
This function block performs variation rate limiter processing.
Condition
(SPR - Rn)  DR
(SPR - Rn)  DR
|SPR - Rn| < DR
SPR: Setting value (%)
DR: Variation rate limit value (%)
Rn: Ratio current value (%)
Rn-1: Last value of ratio current value
10 LOOP CONTROL OPERATION
184
10.1 Ratio Control (Enable Tracking for primary loop) (M+P_R_T)
*1
Recommended Type
range
0 to 100[%] Input variable
0 to 100[%] Input variable
-999999 to 999999[%] Output variable
Recommended Initial value
range
0: Not executed 0
1: Executed
TRUE: Not used TRUE
FALSE: Used
TRUE: Not primary MV TRUE
FALSE: Primary MV
Variation rate limiter processing result (Rn)
Rn = Rn-1 + DR
Rn = Rn-1 - DR
Rn = SPR
Data type
REAL
DWORD
REAL
Set by Data type
User INT
User BOOL
User BOOL