Alcorn Mcbride V+ series, Руководство пользователя

Страница: 249 / 276

15-13 Appendix A
– Adding User-Defined Serial Protocols
Ap
p
end
ice
s
A
The
Byte
field specifies how the byte will be created. There can be up to 20
byte fields. Literal decimal and hex values can be used, as well as functions
that result in a byte or word. The @complex function can not be used.
Currently, 11 operators can be used on the data. They are the following:
Operator Function
+ Add
- Subtract
* Multiply
/ Divide
% Mod (returns remainder from division)
>> Shift Right
<< Shift Left
& Bitwise AND
| Bitwise OR
~ Bitwise NOT
Note
Unlike C language or other ways of expressing mathematical algorithms,
there is no operator precedence. Operations are performed from left to right. If
you wish to specify what operand an operator is to work on, use parenthesis to
group the operand.
Let's look at our complex Search:Time event as an example. Here is the
pertinent information:
param2=timestring, "A valid Time"
byte1=((@minute(param2) / 10 ) << 4 ) | ( @minute(param2) % 10 )
byte2=((@second(param2) / 10 ) << 4 ) | ( @second(param2) % 10 )
byte3=((@frame(param2) / 10 ) << 4 ) | ( @frame(param2) % 10 )
message="C" @complex(byte1) @complex(byte2) @complex(byte3)
The Search to a Time event for a Denon player sends the ASCII byte "C"
followed by a BCD ( binary coded decimal ) representation of the minute, then
the second, then the frame to be searched to.
First, the timestring
param
field takes what the user entered ( let's say
23:12.15 ), and puts 00231215 in the compiler buffer. The message field
directly puts a "C" ( h43 ) into the message, followed by three bytes which are
defined by
byte1
,
byte2
, and
byte3
.
Byte1 takes the third and fourth byte of the compiler buffer, retrieves the
number 23, and puts that into one byte. It then divides that number by 10 and
gets 2. It then shifts left four bits and gets 32 ( h20 ). It then takes that same
minute byte 23, and divides by 10, saving the remainder, not the quotient, which