CHAPTER 5: SETTINGS PRODUCT SETUPC70 CAPACITOR BANK PROTECTION AND CONTROL SYSTEM – INSTRUCTION MANUAL 5-635Datasets used by TxGOOSE1, TxGOOSE2, and/or by reports also provide a chatter suppression service for their Booleanmembers. Oscillation in a value, also known as chatter, can be caused by errors in logic programming, inadequatehysteresis (deadband) on a threshold, or a failed station component. Chatter can flood a communications network withGOOSE messages, degrading response time for all users. If chatter is detected in a Boolean member, TxGOOSE suspendsGOOSE event message triggering and report message triggering from that member for as long as the condition exists, andfor a minimum period of one second. While sending is suspended, a self-test message identifying the specific data itemdetected as oscillating is activated.Navigate to Settings > Product Setup > Communications > IEC 61850 > DataSets > DataSet01 to access the settings forthe first data set. The settings and functionality for the others are similar.DataSet01 nameRange: 0 to 32 VisibleString charactersDefault: DataSet01The value entered sets the name of the data set, which is required to be unique within the UR for proper operation. AnObjectReference to the data set consists of a string that is the concatenation of "/LLN0$" and the DataSet01name setting value. An ObjectReference to the data set is published in the datSet field of TxGOOSE messages, and it canbe used by subscribers to discriminate the messages of that TxGOOSE from other GOOSE messages. An ObjectReferenceto the data set is optionally published in the DatSet field of Report messages. Valid characters are upper and lowercaseletters, digits, and the underscore (_) character. The first character must be a letter.DataSet01 Member1Range: End of List or any instantiated 61850 data object or data attribute with Functional Constraint ST or MXDefault: End of ListThis setting specifies the first member in TxGOOSE1 messages. There is a similar setting for each of the up to 64members that the UR allows in a Dataset. Only values of members before the first set to End of List are published.Deadband settingsA deadband is a range in which no action occurs, expressed as a percentage.The IEC 61850 panels contain hundreds of deadband settings, such as in the following panels: System Setup > SignalSources, FlexLogic, Grouped Elements, Control Elements, and GGIO4. Each panel is not outlined here.Deadband setting names all end either with "DEADBAND" or .db. As they all work the same way, but each on a differentanalog value, a single description applicable to all deadband settings is given here. The analog value that each deadbandsetting applies to is usually obvious from the name of the setting. However, a tabulation of the analog values and theirassociated deadband setting can be found in the UR Series Communications Guide.Figure 5-21: Deadband settings with .db suffixGOOSE, buffered report, and unbuffered report messages are for the most part transmitted only when there is a valuechange in one or more of their members. Most analog values continuously dither by an amount that is not significant.Were a report to be sent each time an insignificant analog value change occurred, then the communications networkfloods with GOOSE and report messages, degrading response time for all users.To control this, a deadband setting is provided for each analog value. Also, in addition to the present actual value of eachanalog ("instMag" in the following figure), there is a deadbanded value ("mag" in the figure), which is updated with thepresent value only when the difference between the two exceeds the deadband setting (db in the figure). Changes to thisdeadbanded value trigger transmissions when included in GOOSE and report data sets.
