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Overview of Direct Connection Operations
Section 5-1
5-1-5 Notifying the Display Screen to the PC
(To Display the Number of Currently Displayed Screen)
The following describes the processing to display the number of currently dis-
played screen of the NT20S.
This processing reads the data from the PC 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 NT20S notifies the following to PT status notify
area (PT to PC) allocated to the PC.
Screen switch notification: Screen switch strobe flag of the PT status word
New screen number: Currently displayed screen word
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 NT20S is dis-
played.
NT20S PC
Currently
displayed
screen
PT status notify area
Currently displayed screen
Screen number
Content upgrade memory table
PT status
Screen switch
strobe flag
[Currently displayed screen] and [PT status] words in the PT status notify
area
1514131211 10 9 8 7 6 5 4 3 2 1 0 Bit
–00 –000
Word
m
15 14 13 12 11 10 9 8 Bit
Screen number (4-digit BCD)
PT status
00PT status
Screen number: 0001 to 0500
m+2
Screen switch strobe
Screen switch setting
Use a 4-digit BCD (binary-coded decimal) value to set a screen number.
The screen switch strobe bit reverts to OFF (0) after this is notified to the PC.