Function Code List - Mitsubishi Electric FR-A820-00046 (0.4K) Instruction Manual

Message field
"0 to 247" can be set in the single-byte (8-bit) length field. Set "0" when sending broadcast messages
(instructions to all addresses), and "1 to 247" to send messages to individual slaves.
Address field
The response from the slave also contains the address set by the master. The value set in Pr.331 RS-485
communication station number is the slave address.
"1 to 255" can be set as the function code in the single-byte (8-bit) length filed. The master sets the function to
be sent to the slave as the request, and the slave performs the requested operation. Refer to the function code
Function list for details of the supported function codes. An error response is generated when a function code other than
field those in the function code list is set.
The normal response from the slave contains the function code set by the master. The error response contains
H80 and the function code.
The format changes according the function code. (Refer to
Data field
count, number of bytes, and accessing content of holding registers.
Errors in the received message frame are detected. Errors are detected in the CRC check, and the 2 bytes length
data is appended to the message. When the CRC is appended to the message, the lower bytes of the CRC are
CRC check appended first, followed by the upper bytes.
field The CRC value is calculated by the sender that appends the CRC to the message. The receiver recalculates
the CRC while the message is being received, and compares the calculation result against the actual value that
was received in the error check field. If the two values do not match, the result is treated as an error.
 Function code list
Read/
Function name
write
Read holding register Read
Preset single register Write
Diagnostics Read
Preset multiple
Write
registers
Read holding register
Read
access log
 Read holding register (reading data of holding registers) (H03 or 03)
• Query message
a. Slave address b. Function
H03
(8 bits)
(8 bits)
• Normal response (Response message)
a. Slave address b. Function
H03
(8 bits)
(8 bits)
Code
The data of the holding registers is read.
The various data of the inverter can be read from MODBUS
registers.
System environmental variable (Refer to
H03
Real time monitor (Refer to
Faults history (Refer to page
Model information monitor (Refer to
Inverter parameters (Refer to
Data is written to a holding register.
Data can be written to MODBUS registers to output instructions
H06 to the inverter or set parameters.
System environmental variable (Refer to
Inverter parameters (Refer to
Functions are diagnosed. (Communication check only)
A communication check can be made since the query message
H08 is sent and the query message is returned as it is as the return
message (subfunction code H00 function).
Subfunction code H00 (Return query data)
Data is written to multiple consecutive holding registers.
Data can be written to consecutive multiple MODBUS registers to
H10 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 and H10 are supported.
H46 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 and H10.
c. Starting address
H L
(8 bits) (8 bits)
e. Byte count
H
(8 bits)
(8 bits)
Description
page 655.) The data, for example, includes the byte
Outline
page 660.)
page 425.)
663.)
page 663.)
page 661.)
page 660.)
page 661.)
page 660.)
page 661.)
d. No. of points
H L
(8 bits) (8 bits)
f. Data
L ...
(8 bits) (n × 16 bits)
5.15 (N) Communication operation parameters
Message
Broadcast format
communication reference
page
Not available page 655
Available page 656
Not available page 657
Available page 657
Not available page 658
CRC check
L H
(8 bits) (8 bits)
CRC check
L H
(8 bits) (8 bits)
5. PARAMETERS
1
2
3
4
5
6
7
8
9
10
655