Hitachi CP-X268AWF User's Manual And Operating Manual page 156

Command format
Command formats differ among the different communication ports.
TCP #23
You can use the RS-232C commands without any changes. The reply data format
is the same as the RS-232C commands. However, the following reply will be sent
back in the event of authentication failure when authentication is enabled.
<Reply in the event of an authentication error>
Reply
0x1F 0x04
TCP #9715
Send Data format
The following formatting is added to the header (0x02), Data length (0x0D),
Checksum (1byte) and Connection ID (1 byte) of the RS-232C commands.
Data
Header
length
0x02 0x0D
Error code
0x00
RS-232Ccommand
8 bits from the header to the checksum.
the reply data)
4. Utilize projector – Advanced -
13 bytes
Connection
Checksum
ID
1 byte 1 byte
77