Rockwell Automation 900-TC32 Digital Temperature Controllers, Series B - Manual (Page 166)

Publication 900-UM007D-EN-E - January 2011
4-30 Parameter Adjustments & Application Considerations
SP Ramp Application Considerations
SP Ramp Operation at Startup
If the SP ramp function is enabled when the Bulletin 900 controller is turned
ON, or when RUN is switched to from STOP, the process value (PV) may
reach the Set Point SP ramp value in the same way as when the set point is
changed. In this case, operation is carried out by the controller with the
process value regarded as the set point before the change was made.
The direction the SP ramp changes is according to the relationship between
the process value and the set point (refer to Figure 4.47).
Figure 4.47
Restrictions During SP Ramp Operation
Auto-tuning execution starts after the end of SP ramp.
When control is stopped or an error occurs, the SP ramp function is disabled.
Time
PV < SP
Set point
SP ramp
Power ON
Time
PV > SP
SP ramp
Set point
Power ON
Same
change rate
SP SP
PV
PV