Hitachi CP-X265 User's Manual And Operating Manual page 103

Reply Data format
The connection ID (the data is same as the connection ID data on the sending
data format) is attached to the RS-232C commands reply data.
<ACK reply>
Connection
Reply
ID
0x06  byte
<NAK reply>
Connection
Reply
ID
0x15  byte
<Error reply>
Reply Error code
0x1C
<Data reply>
Reply
0x1D
<Projector busy reply>
Reply Status code
0x1F
<Authentication error reply>
Authentication
Reply
Error code
0x1F 0x04
Connection
 bytes  byte
Connection
Data
 bytes  byte
Connection
 bytes  byte
Connection
0x00  byte
Command Control via the Network
ID
ID
ID
ID
37