Optimizing A Switch-Point - Honeywell Excel 50 User Manual

Automatic Operation Mode: In the case of automatic operation, the Excel 50
MMI normally processes the values received from the inputs, e.g. from
temperature sensors, while the state of outputs normally shown by the user / time
program is adopted, e.g. "Heating circuit pump off". The feedback loop of the
control system is closed. When the controller is in the automatic operation mode,
the value or the current state being processed by the application program is
contained in the "value" attribute. In the case of an analog input, for example, the
"value" attribute is the current room temperature. In the case of a pump switched
by the digital output, for example, the "value" attribute is the current state (e.g.
"ON").
Manual Operation Mode: During manual operation, the controller uses the
manual values, e. g. "Flow temperature set-point = 60 °C". Outputs adopt the
preselected condition, e. g. "Heating circuit pump on". The feedback loop of the
control system is interrupted. When the controller is in the manual operation
mode, the data specified manually is written into the "manual value" attribute,
processed in the controller, and passed on to an output. The user can, of course,
recall the measured value coming from the "value" attribute, but this has no effect
on the application.

Optimizing a Switch-Point

The optimization function is used to optimize a switch-point. It has two states: "ON"
and "OFF".
Optimization compensates the time an environment needs to reach a desired
condition (temperature, humidity, etc.) by advancing the switch-point of the
corresponding device / actuator so that it starts at an earlier time.
NOTE: The optimization can be set to "ON" only if the given data-point is suitable
for optimization.
Example: If the optimization is set to "ON", a heating plant is switched on early so
that a particular room will be at the required switch-point level by a particular time.
Programmed switch-point:
6:00 to 20 °C
Real switch-point:
4:52 to heating ON
The difference between the programmed and the real switch-point is the
estimated time a room needs to warm up under the current conditions.
EN2B-0222GE51 R0216 62
EXCEL 50 MMI - USER GUIDE