Emerson Rosemount OCX 8800 - Setpoint Selection and Limiting

PID function block schematicFigure 7-14:
7.9.1 Setpoint selection and limiting
The setpoint of the PID block is determined by the mode. You can configure the SP_HI_LIM
and SP_LO_LIM parameters to limit the setpoint. In Cascade or RemoteCascade mode, the
setpoint is adjusted by another function block or by a host computer, and the output is
computed based on the setpoint.
In Automatic mode, the setpoint is entered manually by the operator, and the output is
computed based on the setpoint. In Auto mode, you can also adjust the setpoint limit and
setpoint rate of change using the SP_RATE_UP and SP_RATE_ON parameters.
In Manual mode, the output is entered manually by the operator and is independent of the
setpoint. In RemoteOutput mode, the output is entered by a host computer and is
independent of the setpoint.
Figure 7-15 illustrates the method for setpoint selection.
Foundation Fieldbus
158 OCX 8800