You can write-protect individual lines in the datum table.

1. Open the TNC.sys file in the Programming and Editing mode of operation. It is located directly beneath TNC. If the file is not shown in the file management, change the setting for the SELECT TYPE soft key to SHOW ALL

2. In the file, enter PR.LINESLOCKED = number of lines to be protected. It is possible to protect more than one line. To do this, enter the range, e.g. 14-16. Separate individual lines by a comma e.g. 11,27. 

The control displays the protected lines in red in the DATUM MANAGEMENT.