Turning Off The Screen - Omron NT21 Reference Manual

Buzzer, Backlight, and Display Control
Operation
15 14 13 12 11 10 9 8
0

3-2-4 Turning off the Screen

Reference:
The bit for controlling the PT status (PT status control bit) is provided at the fourth
word (n + 3 words) from the beginning of the PT status control area.
7 6 5 4 3 2 1 0
0
To control the backlight status during the operation of the PT, operate the PT sta-
tus control area as indicated below.
Set 0 (OFF) or 1 (ON) for bit 8 in the fourth word (n + 3 words) from the beginning
of the PT status control area.
Word n + 3, bit 8
To turn the backlight on: 0 (OFF) 1 (ON)
To flash the backlight:
By turning off the screen while it is not in use, the backlight lasts for a long time
and, at the same time, afterimage on the display panel can be prevented. The
backlight is turned off automatically when the screen is turned off. If the screen
saver function is set to Display, however, it is not possible to prolong the life of the
backlight since it is not turned off when the screen is turned off.
The PT provides the following two methods for turning off the screen.
Using the screen saver function of the PT
Operating the PT status control area
Note To prevent the formation of an afterimage, either use the screen saver function
or periodically switch screens.
S The screen can be made to enter the no-display state by specifying screen No.
0. In this state, however, the backlight remains lit or flashing.
S While the screen is in the no-display state, only screen switching operations
from the host are permitted.
S Even though the screen display is set to off, the display of the screen immedi-
ately before the screen is turned off remains output by the PT.
Bit
Controlled Item
Screen display
15
Processing priority registration (for NT link (1:N))
14
Continuous buzzer
13
Intermittent buzzer (short)
12
Display history initialization
11
Not used
10
Intermittent buzzer (long)
9
Backlight mode
8
Screen printing
7
PT window opening
6
Numeral/character string input
5
PT screen switching
4
Memory table copy execution
3
Memory table copy type
2
Alarm history initialization
1
0 Not used
Bits 2 and 3 are not used when the PT is in NT20S or
NT30/620 compatible mode.
Bit 7 is not supported by the NT21.
1 (ON) 0 (OFF)
Section 3-2
1 (ON) 0 (OFF)
Performed Not performed
Registered Canceled
Sounded Stopped
Sounded Stopped
Performed Not performed
Always 0
Sounded Stopped
Lit Flashing
Performed Not performed
Disabled Enabled
Disabled Enabled
Disabled Enabled
Performed Not performed
Numeral Character string
Performed Not performed
Always 0
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