4-30
Chapter 4. Functions
• While AT is running, the MV turns on and off several times to execute the limit
cycle. ("Off" here refers to the fact that the MV is limited by the MV low limit
during AT and by the MV low limit, and the factory setting is 0 %. Also, "on"
refers to the fact that the MV is limited by the MV high limit during AT and by
the MV high limit, and the factory setting is 100 %.) If there is a problem with
this operation, do either of the following.
•
Set the MV low limit during AT and the MV high limit during AT to
appropriate values, and start AT.
•
Do not use AT but set the PID constants manually.
• When heating/cooling control is used, execute AT with both Heat MV and Cool
MV running. In the first half, the MV changes with the output low/high limit
during AT. In the second half, it changes in a somewhat narrow range.
• AT progress is displayed in a graph on the monitor screen.
• It may not be possible to obtain appropriate PID constants, depending on the
control target. In that case, set the PID constants manually.
• The MV ON/OFF switching point determined at the start of AT does not
change even if the SP is changed while AT is running.
• AT can only be started by either the master side or the slave side of the
internal cascade control. Master and slave cannot both start AT.
• If the version of the MAIN block firmware is earlier than 6.x.x (where x stands
for any number), there are no standard bit codes for AT abnormal end (Loops
1 to 4).
To Next Page
Loading...
Need help?
General
