Notifying The Plc Of The Display Screen; (To Display The Number Of Currently Displayed Screen) - Omron NT20S-ST121B-EV3 User Manual

Overview of Direct Connection Operations
1,2,3...
5-1-5

Notifying the PLC of the Display Screen

(to Display the Number of Currently Displayed Screen)

174
Create a PLC ladder program as follows:
00002
00003
11212
Screen switch strobe flag
• Program Operation
1. Screen #2 is displayed on the NT20 when bit 00002 turns ON.
2. Screen #3 is displayed on the NT20 when bit 00003 turns ON.
3. When the screen switch strobe flag turns ON, the number of the currently
displayed screen is read and written to the currently displayed screen word
in the PT status notify area. In this case, the NT20 will not write the same
screen twice.
The following describes the processing to display the number of currently dis-
played screen of the NT20.
This processing reads the data from the PLC status notify area.
To indicate that the screen has switched, use the screen switch strobe flag.
To display the number of the currently displayed screen, use the currently dis-
played screen word.
When the screen has switched, the NT20 notifies the PLC of the following in
PT status notify area (PT to PLC) allocated in the PLC.
Screen switch notification: Screen switch strobe flag of the PT status word
New screen number:
By reading the currently displayed screen word when the screen switch strobe
flag has turned ON, the number of the currently displayed screen on the NT20
is displayed.
NT20
Currently
displayed
screen
@MOV(21)
#0002
Screen number
100
Screen switch setting word
@MOV(21)
#0003 Screen number
100
Screen switch setting word
@MOV(21)
Screen number
110
Screen switch setting word
100
Currently displayed screen word
PLC
PT status notify area
Currently displayed screen
Upgraded memory table entry
PT status
Section 5-1
(1)
(2)
(3)
Screen number
Screen switch
strobe flag