Mitsubishi Electric fr-e700 series, Instruction Manual

Page: 496 / 608

MODBUS®/TCP (FR-E700 SC ENE) Parameter
6 - 342
Read holding register access log (H46 or 70)
●
Queries by function codes H03 and H10 are supported.
The number and start address of holding registers successfully accessed by the previous commu-
nication are returned.
"0" is returned for both the number and start address for queries other than the function codes
above.
●
Query message
●
Normal response (Response message)
●
Query message setting
●
Content of normal response
쐃
Transaction
identifier
쐇
Protocol
identifier
쐋
Length field
쐏
Unit
identifier
쐄
Function
H
(8 Bits)
L
(8 Bits)
H
(8 Bits)
L
(8 Bits)
H
(8 Bits)
L
(8 Bits)
(8 Bits)
H46
(8 Bits)
쐃
Transaction
identifier
쐇
Protocol
identifier
쐋
Length field
쐏
Unit
identifier
쐄
Function
쐂
Starting
address
쐆
No. of points
H
(8 Bits)
L
(8 Bits)
H
(8 Bits)
L
(8 Bits)
H
(8 Bits)
L
(8 Bits)
(8 Bits)
H46
(8 Bits)
H
(8 Bits)
L
(8 Bits)
H
(8 Bits)
L
(8 Bits)
Message Description
쐃
Transaction identifier
The master adds the data for the purpose of transaction control.
The same data is returned in the response from the slave.
쐇
Protocol Identifier
Fixed to 0. (When the slave receives data other than 0, it does not send the response
message.)
0 is returned in the response from the slave.
쐋
Length field The data length from the unit identifier to the data is stored in byte.
쐏
Unit identifier Fixed to 255
쐄
Function Set H46.
Tab. 6-129: Explanation of the query message
Message Description
쐂
Starting address
The start address of the holding register that was successfully accessed is returned.
Starting address = start register address (decimal) - 40001
For example, when start address 0001 is returned, the holding register address that was suc-
cessfully accessed is 40002.
쐆
No. of points The number of holding registers that were successfully accessed is returned.
Tab. 6-130: Explanation of the normal response