Hiwin D2 User Manual

D2 Drive User Guide v1.8 D. Modbus Communication
HIWIN Mikrosystem Corp. 281
D.2. Function code
D2-series drives provide three types of function code, as given in the following table.
Table D-2
Function code
Definition
Message length (bytes)
Command
Response*
Max
Min
Max
Min
03h
Read holding registers
8
8
255
7
04h
Read input registers
8
8
255
7
10h
Write multiple registers
255
11
8
8
*The message length of exception response is 5 bytes.
(1) Read holding registers (03h)
This function is used to read the contents of the consecutive blocks of holding registers in
the drive. The related data format is given in the following table. The content of each
register is divided into the 8-bits higher data (“Hi”) and the 8-bits lower data (“Lo”). The
maximum of consecutive blocks read at the same time is 125.
Table D-3
Data length
Value
Request
Function code
1 Byte
03h
Starting address
2 Bytes
0x0000 - 0xFFFF
Quantity of registers
2 Bytes
1 - 125
Response
Function code
1 Byte
03h
Byte count
1 Byte
2 x N
Register value
2 x N Bytes
Error
Error code
1 Byte
83h
Exception code
1 Byte
01h, 02h, 03h, 04h
Note. N is the quantity of registers.
Table D-4
Exception
code
Exception name
Cause
01h
Illegal function
The function code is not supported.
02h
Illegal data address
Try to read an illegal register.
03h
Illegal data value
The quantity of registers is too large (>125).
04h
Server device failure
The accessed data includes the incomplete data.
For example, the host controller only requests 16
bits of 32-bits parameter.
The following table is an example of requesting to read registers 0x006B - 0x006D. For
the case of normal response, the content of register 0x006B is shown as the 2-bytes
value of “02 2Bh”, the content of register 0x006C is the 2-bytes value of “00 00h”, and the
content of register 0x006D is the 2-bytes value of “00 64h”.

Hiwin D2 Specifications

General

Brand	Hiwin
Model	D2
Category	DC Drives
Language	English