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Groups, servers, and items
To start working with the program, you need to add at least one group with an item. Groups can contain logically united items and each item can be located on a different server. Items from one group can be exported simultaneously, which make it easier to process and export them later. The program allows you to add an unlimited number of groups and items with different properties.
To create a list of groups and items, use the "Groups, servers, and DDE items" tree (fig. 2.8.1). You can use the "Action" button or the popup menu to add, remove, edit, view items, assign other names to them, and also move items and groups. The contents of the popup menu depend on the currently selected tree item (a group or an item).
Fig. 2.8.1 DDE settings
Data source name - you can specify any name that will describe the groups of items and will be displayed in the main window of the program.
Groups, servers, and DDE items - the tree contains groups of servers and items used to receive/send data.
Action – the button allows you to add groups and DDE items to the configuration, remove groups and items, assign new names to items, view and edit data, move groups and items up/down the tree. A click on the button opens a popup menu with the list of actions (fig. 2.8.2).
Fig. 2.8.2 Action menu
The "New group" menu item allows you to add a group of items. A click on this item opens the "Group properties" dialog box (fig. 2.8.3).
Fig. 2.8.3 Group properties.
Name – the field contains the name of the group. The name may contain any characters. By default, it is Group ###, where ### is the number of the group.
Update rate (msec) - the field contains the update rate value for the items in the group. If this option is enabled, the program will forcibly read the values of the DDE items from the server at the specified interval instead of waiting for the notification that the value of an item has been updated. The value is specified in milliseconds. The default is 1000 milliseconds, i.e., 1 second.
Active – the checkbox determines whether the group is active. If it is selected, the items from the group will be read from the server and exported according to the group properties.
Do not export NULL values - the checkbox makes the program not export the value of an item if no item value is received from the server it the program fails to set it to the specified data type.
Wait till all items are updated - if this option is enabled, the items of the whole group will be exported simultaneously at the moment when the values of all items in the group are received. After all items in the group are exported, the internal flag in the program is reset and the program again starts to wait till all items in the group are updated.
Export at fixed interval - if this option is enabled, the values of the items will be exported even if they have not been modified.
Add server name to item name - if this option is enabled, the prefix with the name of the DDE server will be added to the name. It is necessary if the values of DDE items with the same name but from different servers are read.
Export whole group - if this option is enabled, the program will export all items in the group no matter whether their values have been modified or not.
Export one row for all changed items - if this option is enabled, the program will export all items in the group in one line. Otherwise, each item will be exported on a separate line. This option should be enabled if the data will be exported to a database where a separate column is created for every item. This option is available only if the "Export the entire group" option is enabled.
Export date and time stamp - if this option is enabled, the program will automatically add a separate item containing the current date and time during export.
For example: UPDATE_DATE_TIME=2011-09-27 14:09:34
Timestamps in local time - if this option is enabled, the program will use the local time zone to export the date and time stamp. Otherwise, the time will be in the "UTC" time zone.
Export item name - this option is available when items are exported one at a time. If this option is enabled, the program will automatically add a separate item containing the item name during export.
For example: ITEM_NAME="Item2Const";ITEM_VALUE="Time=27.09.2011 0:00:00";UPDATE_DATE_TIME=2011-09-27 14:09:34
The "New DDE item" menu item allows you to add an item to the group. A click on this item opens the "Item properties" dialog box (fig. 2.8.4).
Fig. 2.8.4 Adding an item
File name - the path and name of the DDE server file.
Server - DDE server name.
Topic - describes the group of items on the DDE server.
Item - DDE item name. You can specify several items at once. For example, Item1;Item2;Item3
Type - the item data type. The DDE interface works only with string values. However, you can specify the data type the program should convert the received values to. Later you can apply the corresponding filter and export plug-ins depending on the data type.
The "Remove" menu item (fig. 2.8.2) allows you to remove the selected group with all its items or the separate item selected in the group.
The "Edit" menu item (fig. 2.8.2) allows you to edit the properties of a previously added group or item.
The "Assign another name" menu item (fig. 2.8.2) allows you to specify the item name that will be used for exporting. For example, there is an item named "Item1" on the server. You can assign another clearer name to this item or use it later in filter and data export plug-ins.
The "Up" and "Down" menu items allow you to move the selected item one position up or down in the list. If there is only one group or item in the list or if there are no groups and items at all, the menu item will be unavailable.