The screen save can be controlled from the PLC. 
Use the system information (read device). 
When the Forced Screen Saver Enable signal (System signal 1-1.b1) is turned on and off, the screen saver can be controlled. 
Set the system information using the screen design software.

(Example) Control the screen saver by using D0 for System signal 1-1. 
 The following is an example of a ladder program. 
 (Example 1) Turn on or off D0.b1 according to the value of M0. 
 Figure 1

 (Example 2) Turn on D0.b1 at the rising edge of M0 and turn off D0.b1 at the falling edge of M0. 
 Figure 2

 ◆ For GT Designer3 (GOT2000) Version 1
 1. Select [Common] → [GOT Environmental Setting] → [System Information] to open the [Environmental Setting] dialog.
 2. Select [Use System Information] and configure each setting.
    Figure 3