K-Patents PR-21-S - Manual (Page 79)

8 Troubleshooting 73
DISPLAY
KEYBOARD
H1 interface card Transmitter motherboard
Transmitter processor card
mA outputs
A
B
3 V DC
24 V DC
~
24 V/3 V
DC/DC
Y
POWER G
D16 G
D23 Relay 1 G
D17 Y
D26
G
G
G
R
R
D25 Relay 2 G
Y
Power supply
module
LD1
LD2
LD3
LD4
Figure 8.5 Diagnostic LED functions
8.1.3 Display unreadable
If the display is unreadable because of extreme display backlight and contrast set-
tings or wrong display language, you can perform a display reset. A display reset
will temporarily restore the display backlight and contrast to their factory settings
and will return the display language to English.
For the display reset, you will need to access the DTR keyboard directly. Then do
the following:
1. Switch off the DTR power.
2. Press (hold) down the dot (period/comma) key on the keyboard.
3. Switch on the DTR power.
4. Hold down the dot key until the DTR has started completely and you see the
main display.
Note: The reset on the display language is temporary and the language will return
to original next time the DTR is powered off, except if the language is permantently
changed through the display settings menu.