Rockwell Automation 1766-Lxxxx MicroLogix 1400 Programmable Controllers User Manual - Manual (Page 117)

Rockwell Automation Publication 1766-UM001H-EN-P - May 2014 75
Using the LCD Chapter 5
Valid file type include Bit, Integer, Double integer or Float, as specified in the
TUF element.
The example table below shows how the LCD uses the configuration
information with integer file number 7 (LCD:0.TUF=7).
The data protection for its file depends on the setting for LCD Edit Disable. If
LCD Edit Disable is set to 1 in file properties, the corresponding data file is
considered read-only by the LCD and the “Protected!” message is displayed.
For explanations in this section, we assume the following in the application
program:
• An integer file N7, which is 256 elements long (256 words), is defined with
the preset data, as shown in the screen capture below.
IMPORTANT Use your programming software to ensure that the integer file you
specify in the TUF element, as well as the appropriate number of
elements, exists in the MicroLogix 1400 user program.
IMPORTANT Although you cannot change protected data from the LCD keypad, the
control program or other communication devices have access to
protected data. Protection bits do not provide any overwrite
protection to data within the target integer file. It is entirely the user’s
responsibility to ensure that data is not inadvertently overwritten.
TIP The LCD always starts at word 0 of a data file. It cannot start at any
other address within the file.