Omron NT21 Reference Manual page 321

Screen Display and Notification
Reference: While the PT is running, the screen number of the currently displayed screen is
Example of Use
1, 2, 3...
306
The screen number of the screen displayed at the PT is stored in a 4-digit BCD or
a 4-digit hexadecimal. Whether BCD or hexadecimal notation is to be used is set
for Numeral Storage Type of PT Configuration at the Support Tool. Refer to 2-19
PT Configuration Settings (page 284) for settings related to the PT environment.
always recorded in the screen switch setting word in the PT status control area
(except when the screen displayed is an error screen or the System Menu
screen, in which case the screen number of the screen displayed immediately
before remains recorded).
An example of a PC program that reads the screen number each time the screen
is switched by the PT is described below. This example program stores the pre-
vious screen number also.
Setting with the Support Tool
Set the following words with the Support Tool.
Allocated word in the PT status control area: 00100 (word 100 in the CIO area)
Allocated word in the PT status notify area: 00110 (word 110 in the CIO area)
PC Program
Create the PC ladder program as indicated below.
11112
@MOV(21)
DM0100
DM0101
Screen
switching
strobe @MOV(21)
100
DM0100
Program Operation
1. When the screen switching strobe (bit 11112) comes ON as the screen is
switched by operation at the PT, the program transmits the data at DM0100
to DM0101. The previous screen number is saved to the word provided for
that purpose.
2. The program reads out the new screen number that was notified to the PT to
transmit it to DM0100. The screen number of the screen presently displayed
at the PT is stored to DM0100.
Word for storing the screen number of the previous screen
Word for notifying the screen number of the presently displayed screen
Word for storing the screen number of the new screen
Section 3-3
(1)
(2)