Справочник Пользователя для HP (Hewlett-Packard) ep7100 Series

If your projector has a serial port, you can connect the projector to a room 
controller using a serial (RS-232) cable. After you program the room controller 
using the following commands, you can use the room controller to operate the 
projector and other components of your home theater.

The serial port on the projector uses a standard serial (RS-232) cable:
■ Pin 2: data sent to the projector (RxD)
■ Pin 3: data sent from the projector (TxD)
■ Pin 5: ground
The room controller must use the following serial (RS-232) settings:
■ 9600 baud
■ 1 start bit + 8 data bits (D0=LSB, D7=MSB) + 1 stop bit
■ No parity
■ Full duplex communication channels (no flow control)
■ No handshaking

In the following examples, “<CR>” and “<LF>” represent a carriage return and 
line feed, respectively.

Commands are sent to the projector as "requests" which consist of an asterisk (*) 
prefix, the command name, any needed parameter, and a carriage return <CR> as 
a terminator:

* command = parameter <CR>

Requests can contain only ASCII alphanumeric characters. Blanks (spaces) are 
allowed, except within keywords and numbers. Line feeds <LF> are ignored.