The 18 tells the write() function how many bytes you are sending to Serial2, without that the write() function will stop at the first null (0x00) in the text string. In the code you posted in reply #34 it should be 17 instead of 18 if I counted correctly.
I got the command slightly wrong in the code I posted last week, but I see you found the \x62 for stationary text. Difficult to know for sure when I don't have the hardware here for testing.