What does a DMS Loop Point send out when the setpoint and process variable are equal and only a Proportional constant is used?
DMS and Microsmart
Understanding how to apply a DMS Loop Point to a control application
A proportional-only Loop Point assumes a 'midrange' output when the setpoint and process variable are equal.
'midrange' means midway between the loop output high range and low range (typically 100 and 0 respectively).
For more information, see the DMS Operator Interface User's Guide (F-25467), chapter 13. It is available for download from the Publication Zone.