The PmaTrendGroup object in "Read only (new records cannot be written)" mode

By setting the "Read only (new records cannot be written)" configurator, the PmaTrendGroup object is switched into the mode when it can also read, except the files already created by the PmaTrendGroup object before, the database files (of the dBase, Microsoft Access, MS SQL Server, MySQL and Oracle format) created by any other system. The database table that has to be read by the PmaTrendGroup object, must fulfill the condition that the time column of the Date and time type is defined in there. In the "Read only (new records cannot be written)" mode it is possible to view the data by the PmgTrendViewer viewer, to evaluate the data by the GetData method, etc. But it is impossible to add new records (calling the methods Run, RunTime fails).

In this mode the "Data" tab doesn't define a list of trend variables and it can even be empty. If the list of variables exists (it needn't be complete) and the name of a variable from this list corresponds with the column name in the database table (referred in the PmaTrendGroup object), then the following values entered on the tab - Minimum, Maximum and Displayed name of the trend - serve as the default setting of the variable for the PmgTrendViewer viewer.