<Update Type> Status attributes such as Current Status andPrevious Update Status are common to points on many drivers. They indicate the status of the particular point value to which the attribute relates (as opposed to providing general information about the status of the point itself). For example, a point’s Previous Update Status attribute only indicates the status of that point’s Previous Update Value.
With input points on the IEC 60870-5 driver, <Update Type> Status attributes might display a common value and/or any of these driver-specific values:
You can display a Historic List for an individual point that has Historic Logging enabled (see Historic Lists in the ClearSCADA Guide to Lists).
With IEC 60870-5 points, you use the Logged Data section of the point’s configuration Form to specify whether ClearSCADA is to store Static (current) Data and/or Event (logged) Data historically for a point (see Specify the Type of Point Data that ClearSCADA is to Store Historically) . You can subsequently display that data in the form of a Historic List. Each Historic List comprises a series of rows and columns.
With points on the IEC 60870-5 driver, the Status column can include ‘core’ status information and/or one or more of these IEC 60870-5-specific descriptions:
- Valid—.The status indicates that the value was correctly acquired by the remote device. Applies to allASDU types
- Invalid— This status applies when an abnormal condition has been detected with the information source. For example, a missing or non-operating updating device. The value of the information object is not defined under this condition. This status indicates that the value is suspect and should not be used.
- Carry— This status indicates that counter overflow has occurred when the value is incremented from +231 -1 to zero, or from -231 to zero. Only applies to ASDU 15 interrogated totals.
- Adjusted—A counter is considered to have been adjusted if the counter has been initialized to a value. For example, set to zero or another value at startup. Only applies to ASDU 15 interrogated totals.
- Sequence=n— This status indicates the Sequence number returned by the outstation. Only applies to ASDU 15 iIntegrated totals (n is a value between 0 and 31).
- Overflow— This status indicates that the value of the point is beyond a predefined range of value. This primarily applies to analog values.This is reported by the analog types ASDU 7, 9, 11, and 13.
- Blocked—This status indicates that the value of the information object is Blocked for transmission. The value remains in the state that was acquired before it was Blocked. Blocking and unblocking may be initiated, for example, by a local lock or a local automatic cause. This is reported by point types other than integrated totals ASDU 1,3,5,7,9,11,13 and 15.
- Substituted— This status indicates that the value of the element is provided by the input of an operator ('dispatcher'), or by an automatic source. This status is reported by point types other than integrated totals ASDU 1,3,5,7,9,11,13 and 15.
- Not Topical— This status indicates that a value is Topical if the most recent update was successful. This status is reported by point types other than integrated totals ASDU 1,3,5,7,9,11,13 and 15.
- Transient— This status indicates that a value is moving between positions. This status is reported by Step Position ASDU 5.
- Time Unreliable—This status is reported if the outstation clock is not synchronized for a specified period of time.
- Time Substituted—This status is reported by ASDUs that contain timestamp information.This status is reported when the time has been substituted by intermediate equipment, such as concentrator stations or by the controlling station itself (' substituted time'). The status is also set if the value is reported without a timestamp so that ClearSCADA has to calculate the time stamp.
- Under Test—This status may be reported by all ASDU types. It indicates that the value was logged by the outstation during test conditions.
With each of the above Status values, the associated Quality attribute should provide more information about the reliability of the point’s data and/or the source of the point value.
With IEC 60870-5 input points for which ClearSCADA stores data historically, the above Status values also appear in Historic Lists (see IEC 60870-5 Specific Status Descriptions on Historic Lists).
Further Information
For additional information about <Update Type> Status attributes and other attributes that are common to many types of points, see Status Attributes Associated with Points in the ClearSCADA Guide to Drivers.
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