Applications create Shopping Lists and add requests to the Shopping Lists in order to access Point Management services. Point Management provides the following services through requests:
Requests that cause Point Management to continually supply point values:
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Request Type |
Description |
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On-Change |
Point Management returns the current value of a specified point to the application and then returns the point value every time that the point changes. To stop receiving point values, the application must cancel the request. |
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On-Alarm |
Point Management returns the value of a specified point when it enters into an alarm state. Point Management will continue to send the value whenever the point changes state. To stop receiving point values, the application must cancel the request. |
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On-Acknowledge |
Point Management returns the value of a specified point when the alarm acknowledge status of the point changes. Point Management will continue to send the value whenever the alarm acknowledge status changes. To stop receiving point values, the application must cancel the request. |
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Timed |
Point Management returns the value of a specified point after the expiration of a designated time interval. Point Management reinitiates the interval when it sends point data and sends the point data again after the interval next expires. To stop receiving point values, the application must cancel the request. |
Requests that must be submitted each time a point value is required:
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Request Type |
Description |
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Snapshot |
Point Management returns the current value of a specified point to the application. The application must send the request a second time in order to receive another value. |
Requests to change a point's value or Alarm Parameters.
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Request Type |
Description |
|
Setpoint |
The application sends a data value to Point Management to be downloaded to a device. |
Requests cannot be added to null Shopping Lists. That is, before any add requests are issued for a particular Shopping List, a PTMAP_add_sl must have been issued to define the Shopping List. After requests have been added to a Shopping List, the Shopping List must be sent to Point Management to register the request with a PTMRP.
The subroutines are:
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Create A Shopping List |
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Remove A Shopping List |
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Add "On-Change" Request To Shopping List |
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Add "On-Alarm" Request To Shopping List |
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Receive Change of Alarm Acknowledge State Message |
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Add Timed Point Request To Shopping List |
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Add "Snapshot" Request To Shopping List |
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Add "Setpoint" Request To A Shopping List |
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Disable/Enable An Existing Request |
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Point Management Application Interface overview. |
