The screen number displayed on the GOT can be monitored with the PLC. Perform one of the following operations. 
1. Monitor the screen switching device.
 Set the PLC device for the screen switching device to monitor the device. 
2. Monitor system information.
 Set the PLC device for [System Signal 2-1] in System Information, and select the following items to monitor the device. 
 • [On-screen Window Base Screen Number]: Base screen number
 • [On-screen Window1 Screen Number]: Overlap window 1 screen number
 • [On-screen Window2 Screen Number]: Overlap window 2 screen number
 • [On-screen Window3 Screen Number]: Overlap window 3 screen number
 • [On-screen Window4 Screen Number]: Overlap window 4 screen number
 • [On-screen Window5 Screen Number]: Overlap window 5 screen number
 GT21, GT15, GT14, GT11, and GT10 are only compatible with window screens 1 and 2.

 For details, refer to the screen design software manual.