A cancellation update is created to cancel an ENC. This resets the edition number to zero. A cancellation update indicates that the ENC base cell is cancelled.
Cancellation updates do not modify the information in the database. They operate on files that have already been exported from the database. |
A cancellation update cancels the base cell, updates, and reissue cells. This might be needed when:
• An existing ENC is fully replaced by a re-schemed ENC cell
• A single ENC cell becomes too large and must be split in two
Cancelled ENC cells are not designed to be viewed and therefore cannot be opened in S-57 Composer.
It is recommended that you copy the exchange set and modify the copy: |
1. If necessary, open the Exchange Set Editor.
2. Select the exchange set.
The contents of the exchange set are listed in the dialog box. The base cell (.000) is in the first row.
3. Enable the check box in the Cancel column of the base cell row.
4. [Optional] Click in the Comment field and type a comment about the cancellation.
5. [Optional] Click in the Long File Name field and type a name for the cancellation file.
6. Click Validate.
If any messages are generated, they are displayed in the Validation window.
7. Click Apply.
A message box asks if you want to continue.
If you click Yes, the base cell and any updates are replaced with a single new ENC cancellation update (.00x) file.
8. Click Close.
The cancellation update is completed.
The S-57 ENC exchange set now contains only a special ENC cancellation update file.
The ENC_ROOT folder now contains:
• The updated ENC catalogue file, CATALOG.031.
• A new S-57 ENC cancellation update file which contains the cancellation instructions. If the last update was .003, this will be .004.
• An optional text file which contains information about the exchange set, such as why it was cancelled. This is called README.TXT and can be edited using a text editor.
S-57 ENC cancellation exchange sets cannot be displayed as backdrops in S-57 Composer. If you try to open the ENC base cell, a message is displayed in the Output window to the effect that this ENC is a cancellation and cannot be opened.