21.2.4         Discrete Tag Log

This shows a centralized database for all Discrete Tags for all SCADA Nodes in the project with Data Log to ODBC enabled.

The individual Tags must have both Log Data enabled and Log to ODBC enabled.

From the Project Manager, Project Users can see the Discrete Tag  Log from the 'Project Home' page.

Power Users can also see this Log from VIEW using the Tools menu:
Right Click -> Tools -> Discrete Tag Log.

All Users can also see this Log from ViewDAQ using the menu bar:
Tools -> Discrete Tag Log.

The data can be sorted and filtered by Time, Date, and node addresses.


An optional Tag Name Patterns field isto let users search for patterns using wildcard characters when “All Tags” is highlighted. The wildcard characters are database dependent (.e.g Access, SQL Server, Oracle, MySQL) used to store ODBC data. For an Access database, use % (percent symbol) to match any number of characters and _ (underscore) to match any single character.

An HTML report is printed.

The HTML report displayed can be copied and pasted into EXCEL, WORD and other office applications preserving the cell, column and other formatting.

Data can be exported to EXCEL  (VIEW and ViewDAQ to EXCEL 2000 or later, the Project Manager requires EXCEL 2002 or later).  See 21.3.2 Export to EXCEL from ODBC Log

The default number of records per page for log displays is to 600.

The display used in VIEW is bwdislog.uti.

Data is recorded on a change of state basis. If the Discrete tag does not change, no data is recorded.  The value of the state may range from 0 to 7 (a 3 bit integer) depending on how the Discrete Tag length is configured. A typical Digital tag will have two states (0 and 1). To evaluate the meaning of the state number, you must reference how the tag is configured for each state descriptor.

Length                   State Descriptors Used

                   1-BIT            STATE 0 and STATE 1

                   2-BITS          STATE 0, 1, 2, and STATE 3
3-BITS          STATE 0 thru STATE 7


For related information, refer to Data Log Trend Display in the System & Template Displays section.

BwDiscreteTable : Data log for Discrete tags

a. ProjNodeId : Unique ID for a SCADA node.

b. TagName : Tag Name.

c. LogDate : Date of  the record was recorded.

d. LogTime : Time of the record was recorded.

e. LogMilliSecond : The millisecond of the time of the record was recorded

f. LogValue : The value was recorded.

g. Alarm: If the tag is in alarm during the recording period.

-2147483648 (Decimal) or  0x80000000 (HEX) means there is  no data during the minute of collection.  Otherwise, the value of this field is a LOGICAL OR of all the Alarms that occurred during the interval.

Alarm Code    Alarm Code   Description
Decimal           Hex

-2147483648   0x80000000    no data during the minute of collection.

                2   0x02             Acknowledged Alarm

             512  0x200             Discrete Alarm