MUGL
Page 32 of 38
rev. 18 November 2009
13 Communication protocol V1.1
It’s possible to communicate with the device (send commands and get replies) by means
of the RS485 serial interface, according to a half-duplex communication protocol.
The settings of the communication port is:
Device address:
from 1 to 32
(assigned with appropriate software)
Baud-rate:
9600 b/s
Number of bits:
8
Stop bit:
1
Parity:
None
Each command and each reply are preceded by a start (STX) and the address (IND) of the
device we intend to communicate with, followed by a stop (ETX) and a checksum (CKSUM)
for the data correctness verification.
STX IND Command or reply ETX CKSUM
STX
=
Start character, Hexadecimal value
0x02
IND
=
Device address, added to the hexadecimal value 0x80
(ex. Address 1 = character 0x81)
ETX
=
Stop character, Hexadecimal value
0x03
CKSUM =
Control checksum, it’s a character sum of all characters of the command,
Inclusive of STX and ETX characters, module 256.
Each command that carries a parameter receives a reply with a result character (
ESI
) that
can have the following values:
“0” = Command executed.
“1” = Command not executed.