TRN_EVENT - A trend that is sampled once each time the value of the trigger changes from FALSE to TRUE.You can also define a trigger to stop and start the trend (when a specified condition occurs in the plant). TRN_PERIODIC - A trend that is sampled continuously at a specified period.The type of trend (32 characters maximum): You can leave this field blank in a multi-cluster system if cluster replication is enabled (see the parameter ClusterReplication). This field needs to be defined if your project has more than one cluster. The name of the cluster that runs the trend tag. Two tags accessing the same file can result in system errors which may include lost or corrupted trend/SPC data.įailure to follow these instructions can result in death, serious injury, or equipment damage. If using the File Name property, ensure that the trend tag uses a unique name. Two tags accessing the same file can result in system errors which may include lost or corrupted trend/SPC data. Note: Trend tag names have to be unique and not identical to any SPC tag names within the cluster(s) that run this trend. Note: Where Cluster Name is left blank, the name needs to be unique to every defined cluster. This makes it easier to find and debug your tags. If you have many tags, use a naming convention (see Using structured Tag Names). If the name is not unique or is not syntactically correct it may not be recognized. Trend Tag names need to adhere to the Tag name syntax. The name needs to be unique to the cluster. This will mean an association between the two is easily recognizable. If the trend tag is logging a particular variable, use a 16-character name that resembles the 32-character name of the related variable tag. The name assigned to the trend data (79 characters maximum). If you use one of these reserved words, an error message will display when you compile your project. These reserved words relate to syntax that is used for tag extensions. Note: When entering an Item Name, there are a number of reserved words that you need to avoid. There is a limit of 254 characters across the Equipment and Item Name, including any separating periods (.). They can be used to associate tags, alarms and trends with a particular attribute of a physical piece of equipment (see Items). Items form part of an equipment hierarchy. The name of the item with which the trend tag is associated. There is a limit of 254 characters across the Equipment and Item Name fields, including any separating periods (.). Select a name from the drop-down list of existing equipment definitions, or enter a name. The name of the equipment associated with the trend tag.