Channel Vision Aria A6600, Руководство пользователя

Страница: 23 / 36

21
RS-232 is a serial interface that can be found on many different applications where data or commands need to be
relayed from one location to another. Although this interface can use anywhere from 2 to 25 wires, the basic idea
is that the data is digitized and then sent single file over one wire. The ARIA A6600 uses the interface to receive
remote commands for execution inside the unit.
Since there are many combinations possible in the RS-232 specification, it is necessary that both sending and
receiving equipment agree on the method used. The A6600 is designed to be compatible with the PANJA specifi-
cation. This specification uses:
- line speed of 9600 baud,
- packets consisting of of 8 data bits each, 1 stop bit using No parity,
- DTE to DCE cable known as Straight Through, and
- Sub-D9 Female cable at the A6600 end.
The commands must be programmed as a packet before transmission. The programming method and language is
user-determined (see the pseudo code example).
This illustration shows what a packet causing the A6600 to turn on, to select zone one, DVD, and increase volume
would look like:
Header 1 Header 2 Length 4 TurnOn ZoneOn DVD Vol-Up Checksum
0x16 0x39 0x04 0x2D 0x25 0x18 0x03 0x6C (Values in Hex)
Notice that at the end of this packet’s execution volume will be increased 1 step. To raise volume greater another
packet might be sent consisting of five steps of volume increase as follows:
Header 1 Header 2 Length 5 Vol-up Vol-up Vol-up Vol-up Vol-up Checksum
0x16 0x39 0x05 0x03 0x03 0x03 0x03 0x03 0x0E
(Values in Hex)
UNDERSTANDING RS-232