The Courier database is two-dimensional and resembles a table. Each cell in the database is referenced by a row
and column address. Both the column and the row can take a range from 0 to 255 (0000 to FFFF Hexadecimal.
Addresses in the database are specified as hexadecimal values, for example, 0A02 is column 0A row 02.
Associated settings or data are part of the same column. Row zero of the column has a text string to identify the
contents of the column and to act as a column heading.
The product-specific menu databases contain the complete database definition.
There are two main categories of settings in protection IEDs:
Control and support settings
With the exception of the Disturbance Recorder settings, changes made to the control and support settings are
implemented immediately and stored in non-volatile memory. Changes made to the Protection settings and the
Disturbance Recorder settings are stored in 'scratchpad' memory and are not immediately implemented. These
need to be committed by writing to the Save Changes cell in the CONFIGURATION column.
Courier provides two mechanisms for making setting changes. Either method can be used for editing any of the
settings in the database.
This uses a combination of three commands to perform a settings change:
First, enter Setting mode: This checks that the cell is settable and returns the limits.
Preload Setting: This places a new value into the cell. This value is echoed to ensure that setting corruption
has not taken place. The validity of the setting is not checked by this action.
Execute Setting: This confirms the setting change. If the change is valid, a positive response is returned. If
the setting change fails, an error response is returned.
Abort Setting: This command can be used to abandon the setting change.
This is the most secure method. It is ideally suited to on-line editors because the setting limits are extracted before
the setting change is made. However, this method can be slow if many settings are being changed because three
commands are required for each change.
The Set Value command can be used to change a setting directly. The response to this command is either a
positive confirm or an error code to indicate the nature of a failure. This command can be used to implement a
setting more rapidly than the previous method, however the limits are not extracted. This method is therefore most
suitable for off-line setting editors such as MiCOM S1 Agile, or for issuing preconfigured control commands.
You can extract events either automatically (rear serial port only) or manually (either serial port). For automatic
extraction, all events are extracted in sequential order using the Courier event mechanism. This includes fault and
maintenance data if appropriate. The manual approach allows you to select events, faults, or maintenance data
Chapter 18 - Communications