What does the "Command" in Set and Save Data Lock do?

[madz]

I'm working with a LK204-7T LCD and it randomly displays garbage characters/ messes up it's contrast etc. after rebooting the unit it's fixed on. My suspicion is the mother board is sending some random data towards it via the serial com port and it somehow manages to turn off the set save data lock in the panel.
Previously the Set and Save Data Lock was only locking the display, but since the garbage values persists, I'm experimenting with locking all display, command, settings and address levels. I've noticed that adding `Command` has created more issues in the panel and the documentation is very vague on what each level does.
So does anyone know what locking `Command` will actually do?

[Raquel]

Hello Madz,

Thank you for posting on the forum.

Locking Command means it will ignore all commands; ie data that starts with the command prefix 254.
But It will only toss the data after 254. If the command has parameters, say for example contrast command which has 1 parameter, the display will start displaying this as a character.

Can you share the serial number on your LK204-7T-1U?

Thank you,
Raquel

[madz]

Thanks for the reply Raquel. The serial number is 22M02-1967.
Also on the command lock, it probably filters and see if it's the unlock command before discarding the rest after 254 right?

[Raquel]

Hello madz,

I apologize for not getting back right away.
Yes, that is correct, a check for 202 245 or 203 245 as command parameters is done.

Thank you,