Echelon LonPoint Application and Plug-In - Manual (Page 116)

10-14 Scheduler Interface
when the system is enabled and the outdoor air temperature is cooler than the
indoor air temperature. This transition may put the system into heating mode.
For each transition, you will define an exit condition. An exit condition is a
formula that specifies logical and arithmetic operations on the State Machine
inputs. When the State Machine functional block executes, it evaluates each of
the exit conditions for the transitions defined out of the current state. The first
exit condition that evaluates to true triggers the State Machine functional block
to change states based on the transition being evaluated. The same exit
condition may be used for multiple transitions, as long as each originates from a
different state.
To draw a bubble diagram, follow these steps:
1. Drag an Initial State shape from the LonPoint Schedule stencil to your
LonMaker drawing.
2. Type the name of your initial state, for example stOff.
3. For each of your remaining states, drag a State shape from the LonPoint
Schedule stencil to your LonMaker drawing. Type a name for each state
after you drag it to the drawing. In the following examples, state names
start with an st. Example names are stOn, stOff, stNormal, stOccupied,
stWarmup, and stEmergency.
4. For each transition, drag a Transition shape from the Schedule stencil to
your LonMaker drawing. Drag the end of the Transition shape without an
arrow to the center of the starting state for a transition, then drag the end of
the transition shape with an arrow to the center of the ending state.
5. Click on each Transition shape and type an exit condition name. In the
following examples, exit condition names start with a cnd prefix. Example
exit condition names are cndStartWarmup, cndEmergency, and
cndSystemOff. The same condition exit condition name may be used on
multiple transitions.