Siemens SIMOCODE pro Function Manual page 105

Function code 16 - Write Multiple Registers
Function
This function enables the Modbus master system to write several registers from the
SIMOCODE pro register memory area.
A valid address from the register memory area is expected as the start address. The
selected addresses must be designated as writable (see the tables in Section Modbus RTU
data tables (Page 277), "Access" column).
Typical SIMOCODE parameters that can be written via Modbus RTU are the motor
protection parameters (e.g. rated motor current, trip class) and the warning and trip levels, as
well as delay times of the function blocks.
When writing several registers, they must be marked as a "writable" coherent block. A
register area that is interrupted by read-only registers cannot be written to as a block.
Request message frame
Slave
address
1 byte
Response message frame
Slave address
1 byte
Example
The rated motor current of the SIMOCODE pro with slave address 16, stored as a double
word, is to be changed via Modbus. For this purpose, the new rated motor current of 10 A is
to be written to the device. The expected value is the rated motor current in units of 10 mA,
that is, 10 A = 10,000 mA = 1000 x 10 mA = 03E8h x 10 mA.
Request message frame
Slave
address
1 byte
0x10
Response message frame
Slave address
1 byte
0x10h
SIMOCODE pro - Communication
Function Manual, 11/2018, A5E40508495002A/RS-AC/003
Function Start address Number of
code
1 byte 2 bytes
Function code
1 byte
Function code Start address
1 byte 2 bytes
0x10h 0x41A8
Function code
1 byte
0x10
Number of
registers bytes
2 bytes 1 byte
Start address Number of registers CRC
2 bytes 2 bytes
Number of Number of
registers bytes
2 bytes 1 byte
0x0002 0x04
Start address Number of registers CRC
2 bytes 2 bytes
0x41A8 0x0002
Communication
2.3 Modbus communication
Data CRC
n x 2 bytes 2 bytes
2 bytes
Data CRC
n x 2 bytes 2 bytes
0x0000 0x....
0x03E8
2 bytes
0x....
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