C4-8
IM 34M06H62-02E 2nd Edition : June 2008-00
C4.6 SP Tracking
When a loop is switched from remote to local mode, the SP tracking function
automatically sets the selected Set Point (n.SP) in local mode to the value of the Remote
Set Point (RSP) immediately preceding the switchover.
SP tracking can be used to prevent a drastic change in the CSP when switching from
remote to local mode.
To enable SP tracking, set the SP Tracking Mode (SP.TR) parameter to “0: Tracking on”.
SP tracking acts in the following situations.
- When the Remote/Local Selection (RMT/LOC) parameter is changed from “Remote”
to “Local”.
- When the Automatic/Manual/Cascade Selection (A/M/C) parameter of a secondary
loop in cascade control is changed from “Cascade” to “Automatic” or “Manual”.
Figure C4.5 SP Tracking Operation
Table C4.6 Parameters Related to SP Tracking
Data Position Number
Symbol Description Unit Data Range
Default
Value
Attribute
Stored
Loop1 Loop2 Loop3 Loop4
169 369 569 769 SP.TR SP Tracking Mode None
0: Tracking on
1: Tracking off
1 RW
If you want to store the SP value as the result of SP tracking to EEPROM, you have to
initiate an SP backup procedure. Otherwise, no SP values are stored and, whenever the
module is turned off and then on again, the SP parameters will revert to their last stored
values. For details, see Section B2.4, "How to Back up SP Values to EEPROM."
To Next Page
Loading...
Need help?
General
