TITAN-SVX Software Manual
page 18
Rev 4.01
4.2. MODBUS-RTU
MODBUS RTU uses binary bit values in the message.
Start
Address
Function
Data
CRC
End
Bit
T1-T4
8
8
n x 8
16
T1-T4
Table 4.4
In MODBUS RTU, start message and end message is a silent interval of at least
3.5 characters (T1-T4) times.
Note that all MODBUS RTU messages are binary values. For example, a slave
address of 3 will have binary hex representation of 0x03 which will be an
equivalent ASCII character of EOT (End of Text).
Example 1:
Command from Master to TITAN-SVX for Coil Request
Address
01
(slave address 1)
Function
01
(function 1 – Coil Request)
Data
00
(High Byte - Coil Address)
00
(Low Bye - Coil Address)
00
(High Byte - Number of Coil)
01
(Low Byte - Number of Coil)
CRC
FD
(CRC Low)
CA
(CRC High)
Reply from TITAN-SVX to Master
Address
01
(slave address 1)
Function
01
(function 1 – Coil Request)
Data
01
(Coil Data of 1)
00
(Coil Data)
CRC
51
(CRC Low)
88
(CRC High)
