Siemens SIRIUS 3RW5 Equipment Manual page 106

Messages and diagnostics
7.2 Function Codes
7.2.5 Function Code 15 (Write Multiple Coils)
This function enables the writing of multiple bits from the 3RW5 bit memory area by the
Modbus TCP client system or the Modbus RTU master system.
A valid address from the bit memory area is expected as the start address. The selected
address must be designated as writable in the data tables in chapter Data tables (Page 136).
When writing several bits, they must be identified as a "writable" coherent block. A bit area
that is interrupted by read-only bits cannot be written to as a block.
Request telegram
Modbus TCP:
Address Field Function Code
7 bytes 1 byte
- 0x0F
Modbus RTU:
Slave address Function Code
1 byte 1 byte
- 0x0F
Response telegram
Modbus TCP:
Address Field
7 bytes
-
Modbus RTU:
Slave address
1 byte
-
106
Start address
2 bytes
0x8200
Start address Number of bits
2 bytes 2 bytes
0x8200 0x0007
Function Code
1 byte
0x0F
Function Code
1 byte
0x0F
Number of bits Number of bytes
2 bytes 1 byte
0x0007 0x01
Number of
bytes
1 byte
0x01
Start address
2 bytes
0x8200
Start address Number of bits
2 bytes 2 bytes
0x8200 0x0007
SIRIUS 3RW5 Modbus communication module
Equipment Manual, 03/2020, A5E43676481002A/RS-AC/003
Data
n bytes
0x41
Data CRC
n bytes 2 bytes
0x41 -
Number of bits
2 bytes
0x0007
CRC
2 bytes
-