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Store OPC Readings in the GE Digital APM Database

Steps

1. On the Systems and Tags page, navigate to the OPC system containing the tags for which you want to store readings.
2. Select the OPC Tag for which you want to store readings.

3. At the top of the list, select .

   The datasheet for the OPC Tag record appears.

4. In the Max Readings box, enter the maximum number of readings that you want to store for the tag. You can store a maximum of 600 readings for each tag.

5. In the Readings Time Span box, enter the duration (in milliseconds) for which you want to store readings for the tag.

   Note: You do not have to specify a value in both the Max Readings and Readings Time Span boxes. However, if you do, an OPC Reading record will be created only if the reading value falls within both limits. In addition, a maximum of 600 readings can be stored at any given time, regardless of the time span that you specify.

6. Select OK.

Results

• OPC Reading records will be created automatically according to the settings that you specified.
• The new OPC Reading records will be linked automatically to the corresponding OPC Tag record.

Example: Readings Time Span

Suppose you want to store all reading values that have been captured for a tag in the last 60 minutes. In this case, you would type 3,600,000 in the Readings Time Span text box (3,600,000 milliseconds equals 60 minutes). Then, OPC Reading records would get created automatically to store new readings that were captured in the last 60 minutes. After 60 minutes worth of readings are stored in OPC Reading records, as a new reading value is recorded on the OPC Server, it would be used to create an OPC Reading record automatically, and the OPC Reading record storing the oldest reading value would be deleted automatically. This process would occur continuously as new reading values are recorded on the OPC Server.

Example: Max Readings

Suppose that you want to store ten readings for a tag at any given time. In this case, you would type 10 in the Max Readings text box. Then, ten OPC Reading records will be created to store the last ten reading values for this tag. When the eleventh reading value is recorded on the OPC Server, it will be used to create an OPC Reading record automatically, and the OPC Reading record storing the oldest reading value at that time will be deleted automatically. This process would occur continuously as new reading values are recorded on the OPC Server.

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