Instruction manual

MODBUS Protocol

Function Codes

C-6 Model 5030i SHARP Instruction Manual Thermo Fisher Scientific

Request

Function Code 1 Byte 0x03 or 0x04

Starting Address 2 Bytes 0x0000 to maximum allowed by instrument

Quantity of Registers 2 Bytes 1 to maximum allowed by instrument

Response

Function Code 1 Byte 0x03 or 0x04

Byte Count 1 Byte 2 x N*

*N = Quantity of Registers

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

Response

Field Name (Hex)

Function 0x03

Byte Count 0x06