Matrix Orbital GLC24064 - Manual (Page 8)

1.5 Manual Over-ride
Manual over-ride should only be required in one instance. If for some reason the module is set at a baud
rate which cannot be produced by the host system and all communication to the display is lost, then the user
should follow this simple procedure;
1. Turn off the display
2. Put a jumper on the manual over-ride pins.
3. Power up the display. The baud rate is now set to 19,200.
4. Remove the jumper and change the RS-232 port settings to the desired baud rate.
5. Turn off the display.
6. Power up the display.
Figure 3: Manual over-ride
Refer to the "Set RS-232 port speed", command for acceptable baud rates. This procedure does not
change settings in the memory chip. The procedure uses default settings stored in the main processor, which
allows the user to communicate with the display when all other communications are lost. Once able to
communicate with the display, the user may then change the default settings in the memory chip.
Please note that with the manual over-ride jumper in place, the unit will receive and perform commands
such as turning the backlight on and off. However, it will not output text to the LCD.
1.6 Memory Chip Lock Down
The display uses a memory chip to store speed, start-up screen contrast, fonts, bitmaps and I 2 C settings.
When everything has been changed to the desired settings and the unit is in a finished product or in the field,
locking down the memory chip so no settings can be changed is desirable. This procedure is only to be done
by knowledgeable people.
WARNING Any damage to the display resulting from user error while
performing this procedure will not be covered under the Manufacturer’s
Warranty.
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