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Enter Command Function Differences Depending on the Setting of H5-11
Table 7.5 Enter Command Function Differences Depending on the Setting of H5-11
Function
Time when the parameter settings
When the drive receives the Enter command from the master
are enabled
Checks the upper and lower limits and considers the related parameter
Upper and lower limit check
settings.
Default setting of related
Not affected. The settings of related parameters remain unchanged.
parameters
They must be changed manually, if needed.
Accepts and responds as usual to correct setting data if the data
Fault detection when you set
contains parameter setting errors. The drive discards the disabled
more than one parameter
setting data, but will not return an error message.
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Message Format
The data section of the Modbus packet contains the Modbus message. In this data section, the master sends
commands to the slave, and the slave responds. The message format is configured for both sending and receiving
as shown below, and the length of data packets depends on the command (function) content.
• Unit Identifier
• Function code
• Data
Unit Identifier
This field is used for intra-system routing purposes. It is typically used to communicate to a Modbus+ or a
Modbus serial line slave through a gateway between a Modbus TCP/IP network and a Modbus serial line. This
field is set by the Modbus master in the command and must be returned with the same value in the response by the
slave. This is sometimes referred to as the Unit ID. This field is not usually used because the drive with the option
does not have a gateway function. Refer to the manual of the master or gateway used when you set the value to
the Unit identifier.
Function code
When sent by the master, this field identifies the command to be undertaken by the slave. It also identifies the
format for the DATA section of the message. The slave normally echoes this command back to the master in its
response message. When the most significant bit of this field is set in the response message, it signals an error
condition has occurred.
Data
This field contains multiple bytes of varying length based upon the Function Code for commands and based upon
the results of the command in the response. When sent by the master, this field contains details of the command
that the slave will require to carry out the function. When sent by the slave, this field contains details of the
response and sometimes error information.
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Modbus TCP/IP Option Function Details
03 (03 (Hex.)) Read Multiple Registers
This function code is used to read the contents of a contiguous block of registers. The command specifies the
starting register and the number of registers. The normal response packs two bytes per register. For each register
in the response, the first byte contains the most significant bits and the second byte contains the least significant
bits.
Description
Slave Address (Unit Identifier)
Function Code
Starting Register
Quantity of Registers
*1
N = Quantity of Registers (1 to 16)
YASKAWA SIEP C730600 0IB Modbus TCP/IP Technical Manual
H5-11 = 0
Table 7.6 Read Multiple Registers (Command)
Byte No.
1
1
2
2
7 Modbus TCP/IP Messaging
H5-11 = 1
When you change the parameter settings
Checks the upper and lower limit of the changed parameter only.
Automatically changes the default settings for the related parameters.
Error occurs if only one setting is invalid. The drive discards the data
that was sent.
Data (Hex.)
00 - FF
0000 - FFFF
03
*1
N
29
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