That document has what you need, but it has way more than what you need for basic messages. I've had good and easy luck with the 1-byte command format (baud rate is automatically determined, so I just use 9600 cause the signs we use - the 215C - support that).
My protocol notes:
- At least 5 null bytes to establish baud rate
\x00\x00\x00\x00\x00
- SOH
\x01
- Sign type code, use "
Z" for all sign types
- Sign address, use "
00" for all signs
- STX
\x02
- Command code ("
A" for write text, "B" for read text)
- File label ("
A" through "Z", or "0" for priority)
- ESC (start mode field)
\x1B
- Display position " " (
\x20) for centered (page 18)
- Mode code "
b" for HOLD mode, stationary message (page 89)
- Set color
\x1C (page 82)
- Color
- "
1" Red
- "
2" Green
- "
3" Amber
- "
4" Dim red
- "
5" Dim green
- Message in ASCII characters
- EOT
\x04
I have more notes and a basic module I developed that I can share with you if you want. One thing to keep in mind, you can read and write to multiple "files" on the device. I usually just use one of them since I'm sending it custom text. But if you or someone else writes to the "priority" file, then that's the only thing that will display until that file is cleared, no matter what else you write to any other file. So, use this command to clear the priority file on all signs:
\x00\x00\x00\x00\x00\x01Z00\x02A0\x04. Your specific example should be
\x00\x00\x00\x00\x00\x01Z00\x02AA\x1b b\x1c2hello world\x04.
