During At Loop Disconnection Detection Function - Mitsubishi Electric MELSEC iQ-R Series User Manual

1.30

During AT Loop Disconnection Detection Function

This function detects loop disconnections during AT (auto tuning). A channel that does not follow the control can be detected
by using this function. An error channel can be detected faster than the set time in which the auto tuning ends in failure. The
auto tuning continues even while a loop disconnection detection alert has been issued.
For details on the loop disconnection detection function, refer to the following:
Page 91 Loop Disconnection Detection Function
• This function is enabled even while the peak current suppression function or the simultaneous temperature
rise function is being used.
• The loop disconnection detection dead band setting is disabled for the loop disconnection detection during
AT. (There is no dead band.)
Conditions to start the during AT loop disconnection detection function
• "Valid" has been set for "During AT loop disconnection detection function is enabled/disabled" of "Auto tuning setting" in
"Application Setting."
• A value other than 0 has been set for "Loop disconnection detection judgment time" of "Loop disconnection detection
setting" in "Application Setting."
• The control mode is the standard control. (CH3 and CH4 of the mix control can be used)
The during AT loop disconnection detection function does not work when the above conditions are not satisfied. An error or
alarm does not occur even though the conditions are not satisfied.
■Setting method
1.
Set a value other than 0 for "Loop disconnection detection judgment time." It takes time before the temperature starts
rising due to the dead time of a controlled object. Consider the dead time of each controlled object and set the value.
[Navigation window]  [Parameter]  Target module  [Application Setting]  [Loop disconnection detection setting] 
[Loop disconnection detection judgment time]
2.
Set the following item to "Valid."
[Navigation window]  [Parameter]  Target module  [Application Setting]  [Auto tuning setting]  [During AT loop
disconnection detection function is enabled/disabled]
3.
Execute the auto tuning. ( Page 41 Procedure of auto tuning)
Ex.
For the control in which the temperature rises by 200 for 40 minutes
It takes approximately 24 seconds to raise the temperature by 2. It takes time before the temperature starts rising due to the
dead time of a controlled object. Set the time calculated by adding 24 seconds and the dead time of the controlled object.
For example, when the total dead time is 6 seconds, set 30 for "Loop disconnection detection judgment time" of "Loop
disconnection detection setting" in "Application Setting."
1.30 During AT Loop Disconnection Detection Function
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