Table of Contents
Advertisement
BEL DIGITAL AUDIO
B
M
-
A
1
B
M
-
A
1
Overview
The BM-A1 is automatically placed in the remote mode upon receipt of a valid RS232
command. The front panel can be reactivated by powering off and on or by sending it a
disconnect command.
Commands to be communicated to the remote unit (BM-A1) are arranged in frames. These
frames will then be sent to the remote unit, which will always reply with either ACK for
acceptance or NAK for rejection. Any requested reply then follows in the same frame format.
Frame format
The frame starts with a start character 0xAA (alternating ones and zeros). This is followed by
the destination address, the source address, the command code, the data count, the data, a
checksum and an end flag 0xFE.
Start Flag 0XAA
Destination Address
Source Address
Command
Data Count
Data
Checksum
End Flag 0XFE
Start Flag:
The start flag 0XAA may be sent at any time. If sent during a frame this will cause the frame
to effectively restart.
Destination Address:
This should be set to 1.
Source Address:
This should be set to 1.
Command:
This character is the command for the remote unit and must fall in the range 0X80 to 0XEF.
More details of the relevant codes are shown below.
2004 BEL (Digital Audio) Ltd
BM-A1
s
e r
i
a
l
p
s
e
i
a
l
p
r
o
t
o
c
o
r
o
t
o
c
o
15
BM-A1 serial protocol
l
l
Version 0.2
Advertisement
Table of Contents
