Vg03 Protocol - ADC VelociGraph VG03 Operation Manual

4. Please note that any open spreadsheets must be closed before attempting to LINK
to Excel again.
VI.

VG03 Protocol

VG-03 units can be accessed over an RS-485 network.
The line parameters are:
The messages from the master and those returned from the nodes all have the same format:
Where
<
Is the start of message character, an open angle bracket character, an ASCII
3��
ℎ����
AA Is the address of the target node, encoded as two ASCII hexadecimal digits,
01
to����
ℎ����
is the broadcast address.
CC Is the command being sent, encoded as two ASCII hexadecimal digits. The
commands include:
01
02
03
04
II is the index for the command, usually indicating which register
is being read or written, encoded as two ASCII hexadecimal digits.
aa Is the most significant octet of the data payload, encoded as two ASCII
hexadecimal digits.
bb Is the next most significant octet of the data payload. For a 16-bit payload
(register reads and writes), this is the least significant octet.
cc is the next most significant octet of the data payload. For a 16-bit payload, this is
ignored
Page | 10
Baud rate: 9600
Parity: None
Data bits: 8
Stop bits: 1
<AACCIIaabbccddXX>
. The address 00
ℎ���� ℎ����
read a register
write a register
synchronize clocks
poll for measurements
is reserved for the network master, and ����
ℎ����