Alert Function - Mitsubishi Electric MELSEC iQ-R Series User Manual

1.25

Alert Function

This function issues an alert when a temperature process value (PV) or deviation (E) meets the condition set in advance. Use
this function to activate danger signals of devices or safety devices. Alerts of the alert function are classified into input alerts
and deviation alerts depending on the setting of the alert mode.
• Input alert: Upper limit input alert, lower limit input alert
• Deviation alert: Upper limit deviation alert, lower limit deviation alert, upper/lower limit deviation alert, within-range alert
Input alert
When the temperature process value (PV) is equal to or greater than the alert set value, the system issues the upper limit
input alert.
When the temperature process value (PV) is equal to or smaller than the alert set value, the system issues the lower limit
input alert.
Upper limit input alert
Temperature process value (PV)
Alert set value
Alert status
■Setting method
Set an alert mode. ( Page 79 Alert mode)
• Upper limit input alert: Set "Upper Limit Input Alert" as the alert mode.
• Lower limit input alert: Set "Lower Limit Input Alert" as the alert mode.
Deviation alert
When the deviation (E) between the temperature process value (PV) and the set value (SV) meets a particular condition, the
system issues the deviation alert.
The set value (SV) to be referred to is either "Set value (SV) monitor" or "Set value (SV) setting" depending on the set alert
mode. When a setting variation rate limiter has been set, "Set value (SV) monitor" follows the set value (SV) at the specified
variation rate.
The following table shows the application of each set value (SV) of when a setting variation rate limiter has been set. When
the deviation alert is used, refer to the following:
Reference target of the set value (SV)
'CH1 Set value (SV) monitor' (Un\G406)
"Target Value(SV) Setting" of "Control basic
parameters" in "Application Setting"
1 FUNCTIONS
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1.25 Alert Function
Time
Non-alert status Alert status
Application (when the set value (SV) has changed)
This value is used when the temperature process value (PV) needs to follow the changing set value (SV)
within a certain deviation (E).
When the temperature process value (PV) does not follow the set value (SV) and goes out of the set
deviation (E), an alert occurs.
This value is used when the temperature process value (PV) does not need to follow the changing set value
(SV) and only the deviation (E) to the set value (SV) is used for the judgment of an alert.
Even while the value in 'CH1 Set value (SV) monitor' (Un\G406) is changing, an alert is judged based on the
deviation (E) to the set value (SV).
Lower limit input alert
Temperature process value (PV)
Alert set value
Alert status
Time
Non-alert status
Alert status