Scheduled Events

From SysCADWiki

Navigation: Main Page -> Models -> Process Control Models

This model was released as part of build 126.

This model is used in Dynamic Simulation only.

The Scheduled Events unit operation can be used to simulate downtime of a piece of equipment due to a scheduled event such as maintenance or plant shutdown. The model allows one tag to be set to different values depending on whether the unit is active or inactive due to a scheduled event.

Tag / Symbol	Input / Calc	Description
Mode;
Tag	Output	Displays the tag name of the unit.
Condition	Output	OK if no errors, otherwise displays error message.
EqpDesc	Input	Optional unit description field.
On	Tick box	Switch the unit on (ticked) or off (cleared).
IntegralPeriod	Tick box	This relates to the active period of the unit between scheduled events. If this box is ticked, then SysCAD may adjust the active period entered to suit the stepsize of the project. For example, if the step size is 1 hour, and the period given is not an exact number of hours, then SysCAD will adjust this number to make it an exact number of hours. If this box is left clear, then SysCAD will use the exact number entered. This may lead to some unevenness in the periods but the total amount of active time will be correct over a long period of time.
IntegralInactivePeriod	Tick box	This is the same as IntegralPeriod except it relates to the inactive period of the unit due to the scheduled event. If this box is ticked, then SysCAD may adjust the inactive period entered to suit the stepsize of the project. If this box is left clear, then SysCAD will use the exact number entered. This may lead to some unevenness in the periods but the total amount of inactive time will be correct over a long period of time.
Count	Input	The number of independent scheduled event blocks required. This may be any number from 0 up to 20. The user may also change this number at any time except when the model is running. The unit will always add new downtime blocks after existing ones, and it will delete them starting from the last block. E.g. if you have 5 scheduled event blocks set up and you change this to 4, scheduled event block number 5 will be deleted.
Reset_All	Button	This will reset the results values and restart any offsets.
Each independent scheduled event block has the following layout. Additional tab pages will be added as required to fit more scheduled event blocks.
SE.[Scheduled Event Block number]
Requirements...
Desc	Input	Optional scheduled event block description.
RqdPeriod	Input	Required Period - The time period from the start of one scheduled event to the start of the next scheduled event.
Offset	Input	The time period before the first scheduled event will occur. This time is reset if the reset button is pressed.
RqdInactive_Period	Input	Required Inactive Period - The time period of the downtime due to the scheduled event, ie. how long the equipment is inactive.
ActiveVal	Input	The value to set tag to (see below) when equipment is active (ie. not stopped due to the scheduled event). This input is optional.
InactiveVal	Input	The value to set tag to (see below) when equipment is inactive due to the scheduled event. This input is optional.
TagToSet	Input	The tag to be set to different values (as defined above) when the equipment is active or inactive due to the scheduled event. This input is optional. An example would be the flowrate on a feeder or the flow in a splitter.
Results...
Period	Output	The time period from the start of one scheduled event to the start of the next scheduled event. This may be slightly different to the number entered if the IntegralPeriod option has been selected.
InactivePeriod	Output	The time period of the downtime due to the scheduled event, ie. how long the equipment is inactive. This may be slightly different to the number entered if the IntegralInactivePeriod option has been selected.
Active	Output	The current state of the equipment, expressed as a numerical value. This value could be referenced in PGMs for example to perform a series of tasks depending on the state of the equipment. If the equipment is active, then the value is 1. If the equipment is inactive due to the scheduled event then the value is 0.
Output	Output	The value that TagToSet is set to (if specified).
TtlInactiveTime	Output	The total amount of inactive time due to the scheduled event since the model was last reset.
TimeToNextInactivePeriod	Output	The amount of time until the next inactive period due to the scheduled event.
NextEvent	Output	The time and date of the next scheduled event.