Omron E5CN User Manual page 119

Using the SP Ramp Function to Limit the SP Change Rate
Operation at Startup
Restrictions during
SP Ramp Operation
Alarms during SP
Ramp Operation
94
If the SP ramp function is enabled when the Controller is turned ON or when
switching from STOP to RUN mode, the process value reaches the set point
using the SP ramp function in the same way as when the set point is changed.
In this case, operation is carried out with the process value treated as the set
point before the change was made. The direction of the SP ramp changes
according to the relationship between the process value and the set point.
PV < SP
SP
SP ramp
Set point
PV
Power ON
• Execution of auto-tuning starts after the end of the SP ramp.
• When control is stopped or an error occurs, the SP ramp function is dis-
abled.
The operation of alarms during SP ramp operation depends on whether
alarms are set to be based on the ramp set point or the target set point (refer
to the following diagrams). The set point to be used is set in the Alarm SP
Selection parameter. (Refer to page 225.)
Alarm SP Selection = Ramp SP (Alarm Type: 1 (Upper/Lower Limits))
Temperature
Alarm SP Selection = Target SP (Alarm Type: 1 (Upper/Lower Limits))
Temperature
SP
PV
Set point
Time
Power ON
Alarm output ON
Alarm output ON
Time
Alarm output ON
Alarm output ON
Time
Section 4-7
PV > SP
SP ramp
Same rate
of change
Time