Emerson P/N 400361-00 manual User Variables View, Queue Object and Components Diagram

QueueClear

Data In

CompareEnable

Set # of Queue Objects = 0 and clear data in queue

Full

Level

Queue

Size

Data Out

Queue Offset

Sum

IF (# of Queue

Objects = 0)

IF (# of Queue

Objects = or > Full Level)

Source Select:

MasterPosn

FeedbackPosn

CommandPosn

Comparitor

Exit Position

QueueEmpty

QueueFull

QueueExit

Clear

Compare

Enable

Figure 81:

	Queue Object
Data[ ]			Exit
			Empty
Size
Offset
Full Level			Full
Comparitor Select
Name
			Overflow
Data In		Data Out
Queue Data = X		Y = Queue Data

Queue Object and Components Diagram

7.3.14 User Variables View

IF (# of Queue Objects = Queue Size)

QueueOverflow

User variables allow the user to store data related to their application into a parameter, which the user can name.

Figure 80: Queue Block Diagram

Sources

Queue Exit - This source activates when the Comparator Select parameter is greater to or equal to the sum of the data entered into the queue, and the queue offset.

Queue Empty - This source is active if no data is stored in the queue. It will become inactive when the first piece of data is loaded into the queue and remain inactive until all data has been removed from the queue.

Queue Full - The Queue Full source will activate if the number of pieces of data in the queue equals or exceeds the Full Level parameter. The source will deactivate when the number of pieces of data in the queue is less than the Full Level.

Queue Overflow - This source activates when there is no more room in the queue to store data. The maximum number of pieces of data is determined by the Queue Size parameter.

Destinations

Queue Clear - This destination automatically clears all of the data out of the queue. The cleared data is not saved and there is no way to recover the cleared data. This is typically activated on power-up of the system to make sure no old data remains in the queue.

Queue Compare Enable - The Compare Enable causes the comparator internal to the queue to function. If the Compare Enable is inactive, then the Queue Exit source will never activate.

If activated, then the Queue Exit source will activate when the Queue Data plus the Queue Offset is greater than or equal to the Comparator Select parameter.

To fully understand the operation of the queue, Figure 81 has a more detailed view of the Queue object.

The user must define each user variable by giving it a Name, Resolution (number of decimal places), and Initial Value. All user variables are signed 32-bit parameters. Figure 82 shows an example of the User Variables view.

Figure 82: User Variables View

The following parameters are part of the User Variable definition:

Name - This is a twelve-character string that allows the user to assign a descriptive name to the parameter. Spaces are not allowed in the name of a user variable.

Decimal - This parameter defines the number of digits (up to 6) to be used after the decimal point for the specific variable. This is the maximum resolution that the parameter will have.

Initial Value - This is the initial value of the user variable that will be used on power up. If the user variable has been configured as a Save to NVM parameter, then the value in NVM will overwrite the initial value on power up.

Configuring an Application www.emersonct.com 49