Mitsubishi Electric MELSEC iQ-R Series Programming Manual page 451

■Tracking (PID parameter)
When all the following conditions for tracking PID parameters are satisfied, this function block tracks PID parameters for
heating and cooling to the primary loop.
• PRM_TRK = 1
• SVPTN_B0 = FALSE
• SVPTN_B1 = FALSE
The following table shows the description on the processing.
The PID parameter to be tracked is selected with the following expressions.
Condition
PID parameter for cooling is being tracked: SV  SPLT + HS
PID parameter for cooling is being tracked: SV < SPLT + HS
PID parameter for heating is being tracked: SV  SPLT - HS
PID parameter for heating is being tracked: SV < SPLT - HS
SV: Primary loop MV, SPLT: Split median, HS: Hysteresis (%)
• Switching from PID parameter for cooling to PID parameter for heating
With heating PID constant
With cooling PID constant
0%
• Switching from PID parameter for heating to PID parameter for cooling
With heating PID constant
With cooling PID constant
0%
The following table lists the operations when the condition for tracking the PID parameters shown above are satisfied for the
first time.
Condition
SV  SPLT
SV < SPLT
• When the tag type of the primary loop is PID, 2PID, 2PIDH, PIDP, SPI, IPD, or BPI, the PID parameters are
tracked. (When the tag type of the primary loop is SPI or BPI, the parameters to be tracked are
"PROPORTIONAL" (+52) and "INTEGRAL" (+54).)
• To track PID parameters, set initial values in the PID parameters for heating and cooling of this tag FB. Do
not set the PID parameters in the primary loop.
• Switching timing of PID parameters can be adjusted with a hysteresis.
PID parameter to be tracked
PID parameters for heating (P_HT, I_HT, D_HT)
PID parameters for cooling (P_CL, I_CL, D_CL)
PID parameters for heating (P_HT, I_HT, D_HT)
PID parameters for cooling (P_CL, I_CL, D_CL)
HS
SPLT
HS
SPLT
PID parameter to be tracked
PID parameters for heating (P_HT, I_HT, D_HT)
PID parameters for cooling (P_CL, I_CL, D_CL)
12.40 Heating and Cooling Output (M+M_HTCL_T_)
SV(%)
SV(%)
12 LOOP TAG
12
449