Mitsubishi Electric FR-F820-00046, Instruction Manual

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Ethernet communication (FR-F800-E) Parameters
5 - 602
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
Transaction
identifier
Protocol
Identifier
Length field Unit identifier Func-
tion
H
(8 bits)
L
(8 bits)
H
(8 bits)
L
(8 bits)
H
(8 bits)
L
(8 bits)
(8 bits)
H46
(8 bits)
Transaction
identifier
Protocol
Identifier
Length field Unit identifier Func-
tion
Starting
address
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
Transaction identifier
The master adds the data for the purpose of transaction control.
The same data is returned in the response from the slave.
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.
Length field The data length from the unit identifier to the data is stored in byte.
Unit identifier Fixed to 255
Function Set H46.
Tab. 5-317: Description of the query message
Message Description
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
successfully accessed is 40002.
No. of points The number of holding registers that were successfully accessed is returned.
Tab. 5-318: Description of normal response