ES58 • EM58 MODBUS®
Request PDU
Function code
1 byte
04 hex
Starting address
2 bytes
0000 hex to FFFF hex
Quantity of Input Registers
2 bytes
0000 hex to 007D hex
Response PDU
Function code
1 byte
04 hex
Byte count
1 byte
2 x
N*
Input register value
N*
x 2 bytes
*N = Quantity of registers
Exception Response PDU
Error code
1 byte
84 hex (=04 hex + 80 hex)
Exception code
1 byte
01 or 02 or 03 or 04
Here is an example of a request to read the
parameter (input registers 2 and 3).
Request
Response
Field name
(Hex)
Field name
(Hex)
Function
04
Function
04
Starting address Hi
00
Byte count
04
Starting address Lo
01
Register 3 value Hi
00
Quantity of Input Reg. Hi
00
Register 3 value Lo
00
Quantity of Input Reg. Lo
02
Register 4 value Hi
2F
Register 4 value Lo
F0
As you can see in the table, the
Current position [0001-0002 hex]
(input registers 2 and 3) contains the values 00 00 hex and 2F F0 hex, i.e. 12272
in decimal notation.
MAN ESx58x_EMx58x MB E 1.3
MODBUS® interface
58 of 92
Содержание EM58 MB
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