MODBUS Protocol
Function Codes
C-6
Partisol 2000
i
and Partisol 2000
i
-D Instruction Manual
Thermo Fisher Scientific
Request
Function code
1 Byte
0x03 or 0x04
Starting Address
2 Bytes
0x0000 to maximum allowed by Sampler
Quantity of Registers
2 Bytes
1 to maximum allowed by Sampler
Response
Function code
1 Byte
0x03 or 0x04
Byte count
1 Byte
2 x N (N = quantity of registers)
Register value
N* x 2 Bytes
N = N or N+1
Error Response
Function code
1 Byte
Function code + 0x80
Exception code
1 Byte
01=Illegal Function, 02=Illegal Address,
03=Illegal Data, 04=Slave Device Failure
Here is an example of a request and response to read registers 10–13:
Request
Field Name
(Hex)
Function 0x03
Starting Address Hi
0x00
Starting Address Lo
0x09
No. of Registers Hi
0x00
No. of Registers Lo
0x04
