dbx quick_guide User Manual
Page 3
A function to calculate the ccitt value can be implemented in ‘C’ as:
UCHAR update_bcc(UCHAR current_bcc, UCHAR new_value)
{
return Network_CCITT_8_Table[current_bcc ^ new_value];
}
If your controller does not implement logic functions, these can be implemented using
lookup tables. There are plenty of resources on the web on how to do this.
The ccitt table can be found in a file ccittbl.h.
A few messages:
Program Change:
A program change can be done by issuing a Program Retrieve command followed by a
Program Load command. Here are datagram strings that load programs 1 – 4 from a
controller attached to DriveRack with device address 1.
MSG_PROGRAM_DO_RETRIEVE
<0x005A>
Byte
Program_Number
MSG_PROGRAM_DO_LOAD
<0x005C>
(no parameters)
Load Program 1:
MSG_PROGRAM_DO_RETRIEVE
1
77
3
5A
0
0
C4
MSG_PROGRAM_DO_LOAD
1
77
2
5C
0
5F
Load Program 2:
MSG_PROGRAM_DO_RETRIEVE
1
77
3
5A
0
1
9A
MSG_PROGRAM_DO_LOAD
1
77
2
5C
0
5F
Load Program 3:
MSG_PROGRAM_DO_RETRIEVE
1
77
3
5A
0
2
78
MSG_PROGRAM_DO_LOAD
1
77
2
5C
0
5F
Load Program 4:
MSG_PROGRAM_DO_RETRIEVE
1
77
3
5A
0
3
26
MSG_PROGRAM_DO_LOAD
1
77
2
5C
0
5F
Mutes:
MSG_CONFIG_WRITE_MUTE_STATUS 0x00B8
bits
Mute channels 1,2,3,4
1
77
3
B8
0
F
D
Mute all:
1
77
3
B8
0
FF
79
Unmute all:
1
77
3
B8
0
0
4C