General Information
CTV Duplex Sequence Of Operation This section will provide basic information on chiller operation for common events. With microelectronic controls, ladder diagrams cannot show today’s complex logic, as the control functions are much more involved than older pneumatic or solid state controls. Adaptive control algorithms can also complicate the exact sequence of operation. This section and its diagrams attempt to illustrate common control sequences.
The Sequence of Events diagrams use the following KEY:
Software States: (Figure 7)
There are five generic states that the software can be in:
1.Power Up, Stopped, Starting, Running, Stopping
Timeline Text: (Figures 8-11)
The large timeline cylinder indicates the upper level operating mode, as it would be viewed on DynaView. Text in Parentheses indicates
Power Up Diagram:
The Power up chart shows the respective DynaView screens during a power up of the main processor. This process takes from 30 to 50 seconds depending on the number of installed Options. On all power ups, the software model always will transition through the ‘Stopped’ Software state independent of the last mode. If the last mode before power down was ‘Auto’, the transition from ‘Stopped’ to ‘Starting’ occurs, but it is not apparent to the user.
Software Operation Overview Diagram:
The Software Operation Overview is a diagram of the five possible software states. This diagram can be thought of as a State Chart, with the arrows, and arrow text, depicting the transitions between states.
The text in the circles are the internal software designations for each State.
Figure 7. Sequence of operation overview.
The first line of text in the Circles are the visible top level operating modes that can be displayed on Dyna View. The shading of each software state circle corresponds to the shading on the timelines that show the state that the chiller is in.
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