Mitsubishi Electric MELSEC iQ-R Series Programming Manual page 606

Ex.
Tracking of loop selector
TIC
PV1
001
Loop 1
TIC
PV2
002
Loop 2
(1) MV of SEL (loop selector) is transferred to the primary loop when the control mode of SEL is manual (MANUAL, COMPUTER MV) or when the variation rate
and high/low limiter alarm occurs in other than the MANUAL (AUTO, CASCADE, COMPUTER SV) mode.
The primary loop with tracking setting to the SEL is tracked.
■Cascade connection when tracking is required
Connect CASOUT_T of the primary loop with CASIN_T of the secondary loop. The tag FB of secondary loop should be the
one with CASIN_T (such as (M+M_PID_T, M+M_2PID_T).
(1)
(1) Primary loop
(2) Secondary loop
When tracking is executed, tracking setting for the operation constant of the secondary loop tag FB is required.
Variable name
PID_TRK
PID_SVPTN_BO
PID_SVPTN_B1
APPX
604
Appendix 3 Related Functions of Process
MV
SEL
MV
Loop 3
(2)
Description Range
Tracking flag 0: Without tracking
1: With tracking
Setting value (SV) used TRUE: Not used
FALSE: Used
Setting value (SV) pattern TRUE: Not primary MV
FALSE: Primary MV
(1)
MV
Initial value
0
TRUE
TRUE
Setting for tracking
1
FALSE
When the primary loop is the tag FB: FALSE
(typically FALSE)
When the primary loop is not the tag FB: TRUE