Mitsubishi Electric 800 Series Instruction Manual page 61

Function name
Write Multiple Registers
Read holding register
access log
 Read holding registers (reading data of holding registers) (H03 or 03)
• Query message
a. Transaction
identifier
H L H
(8 bits) (8 bits) (8 bits)
• Normal response (Response message)
a. Transaction
identifier
H L H
(8 bits) (8 bits) (8 bits)
• Query message setting
Message
a Transaction identifier
b Protocol identifier
c Length field
d Unit identifier
e Function code
f Starting address
g Quantity of registers
• Content of normal response
Message
h Byte count
i Register value
 Example) Read the register values of 41004 (Pr.4) to 41006 (Pr.6) from the inverter.
Query message
Transaction
Protocol identifier
identifier
H00
*1 *1
(8 bits)
*1 A given value is set.
Normal response (Response message)
Transaction
Protocol identifier
identifier
H00
*1 *1
(8 bits)
60
2. Ethernet Communication
2.7 MODBUS/TCP
Read/write Code
Write H10
Read H46
b. Protocol
c. Length field
identifier
L H L
(8 bits) (8 bits) (8 bits)
b. Protocol
c. Length field
identifier
L H L
(8 bits) (8 bits) (8 bits)
The master adds the data for the purpose of transaction control.
The same data is returned in the response from the slave.
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.
The data length from the unit identifier to the data is stored in byte.
Fixed to 255
Set H03.
Set the holding register address from which to start reading the data.
Starting address = start register address (decimal) - 40001
For example, when starting register address 0001 is set, the data of holding register address 40002
is read.
Set the number of holding registers for reading data. Data can be read from up to 125 registers.
The setting range is H02 to HFA (2 to 250).
Twice the number of reads specified by (g) is set.
The amount of data specified by (g) is set. Read data is output Hi bytes first followed by Lo bytes,
and is arranged as follows: data of start address, data of start address+1, data of start address+2,
and so forth.
Length field
H00 H00 H06
(8 bits) (8 bits) (8 bits)
Length field
H00 H00 H09
(8 bits) (8 bits) (8 bits)
Outline
Data is written to multiple consecutive holding registers.
Data can be written to consecutive multiple MODBUS registers to
output instructions to the inverter or set parameters.
System environmental variable (Refer to
Inverter parameters (Refer to
The number of registers that were successfully accessed by the
previous communication is read.
Queries by function codes H03, H06, and H10 are supported.
The number and start address of holding registers successfully
accessed by the previous communication are returned.
"0" is returned for both the number and start address for queries
other than function code H03, H06, and H10.
When the connection is closed, the data in the log is cleared.
d. Unit e. Function
identifier
H03
(8 bits)
(8 bits)
d. Unit e. Function
identifier
H03
(8 bits)
(8 bits)
Description
Description
Unit identifier Function code
HFF H03
(8 bits) (8 bits)
Unit identifier Function code
HFF H03
(8 bits) (8 bits)
page 64.)
page 66.)
f. Starting
code address
H L
(8 bits) (8 bits)
h. Byte
i. Register Value
code Count
H
(8 bits)
(8 bits)
Starting address
H03 HEB
(8 bits) (8 bits)
Byte
count
H06 H17
(8 bits) (8 bits)
Message
format
reference page
page 62
page 63
g. Quantity of
registers
H L
(8 bits) (8 bits)
L ...
(8 bits) (n × 16 bits)
Quantity of
registers
H00 H03
(8 bits) (8 bits)
Register value
H70 H0B
(8 bits) (8 bits)