Echelon LonPoint Application and Plug-In - Manual (Page 94)

9-10 PID Controller Functional Block
Default Values The default value for the controlled variable output.
This value will be set in case of a heartbeat failure
or if the PID is disabled using the Enable input.
Controlled Variable Override Sets the value of the controlled variable output when
this PID functional block is put into override mode.
Actual Auto/Manual Override The Auto_Man_Out network variable indicates
whether the PID is in Auto (On Auto_Man_Out
output) or Manual (Off Auto_Man_Out output)
operation. In situations where PID controllers are
cascaded, with the inner-loop controller taking its
setpoint from an outer-loop controller’s CV network
variable, the outer-loop controller must know the
Auto/Manual
setting of the inner loop controller.
This is illustrated in the following figure. When the
inner loop controller is in override, it is not
controlling and is in Manual operation.
This configuration property determines the value of
the Auto_Man_Out output when this PID
functional block is put into override. Set the value to
Manual
to accurately reflect the actual auto/manual
setting when the PID is in override.