Delay

Partial model of a delay for CLD+ modeling

Diagram

Information

This information is part of the Business Simulation Library (BSL).

This is a fairly elaborate class serving as a building block for delay components. Since inflows to and outflows from a stock should be modeled using the same component, the class provides machinery to either deduct outflowing material at once or after it has left the stock (at the end of the delay process).

The delayTime is given by a parameter, that is (optionally) multiplied by an exogenous input u as to enable exogenous input of delay times (e.g., delayTime = 1 and hasFactor = true) or have the time of delay be modified by other variables.

The stock value reported at the stock port portA is determined from the choices made with regard to outflowing material (deducted or not), while the flags are immediately copied from the flow port portB.

Implementation

DiagramView

  <...> 
protected
  parameter Real k2 = if subtractDelayedOutflow then -1 else 0 \
      "Gain of outflowing elements of stock B being delayed";
  <...>
equation
  // set stock port variables
  portA.stopInflow = portB.stopInflow;
  portA.stopOutflow = portB.stopOutflow;
  portA.stock = actualStockB.y;
  // set rate inputs
  growthRate = if portA.rate >= 0 then portA.rate else 0;
  declineRate = if portA.rate < 0 then -portA.rate else 0;
  <...>

Parameters (6)

delayTime	Value: 1 Type: Time (s) Description: Time of delay
subtractDelayedOutflow	Value: true Type: Boolean Description: = true, if a delayed outflow is to be deducted before it actually leaves the stock
hasFactor	Value: false Type: Boolean Description: = true, if coefficients are to be multiplied with input u
hasStockInfoOutput	Value: false Type: Boolean Description: = true, if information from the internal 'in process' stock is to be made accessible
IDI	Value: 0 Type: MaterialType Description: Initial material in the process of flowing into the connected stock
IDO	Value: 0 Type: MaterialType Description: Initial material in the process of flowing into the connected stock

Connectors (7)

	portA	Type: StockPort
	portB	Type: FlowPort
	u	Type: RealInput Description: Factor input
	stockInfoOutput	Type: StockInfoOutput
	one	Type: RealOutput Description: Default factor
	growthRate	Type: RealOutput Description: Indicated rate of growth
	declineRate	Type: RealOutput Description: Indicated rate of decline