Thanks, any return value is fine for automatic checking that the module is responding properly. I'll try this again, but I'm sure I got no data back at all.

PS I found this table of information in the command list for the GLK12232-25, which seems to imply it works for my LK204-25.

Hi, I'm using an LK204-25 with Linux, however I don't get an error message when I attempt to open the port and communicate with the LCD when it's powered down.

I was hoping to be able to read something back from the module to indicate it is alive and well, when I found the following commands in a ...