RLE LD1500 V.3.1 - Manual (Page 41)

rletech.com LD1500 User Guide 41
5 Modbus Communication
5.2.3 Function 06: Preset Single Register
To set a LD1500 parameter value, the master must send a Preset Single Register request
packet. The Preset Single Register request packet specifies a register and the data to write to
that register. The register is numbered from zero (40001 = zero, 40002 = one, etc).
5.2.4 Function 16: Preset Multiple Registers
To set multiple LD1500 parameter values, the master must send a Preset Multiple Registers
request packet. The Preset Multiple Register request packet specifies a starting register, the
number of registers, a byte count and the data to write to the registers. The register is
numbered from zero (40001 = zero, 40002 = one, etc).
Table 5.7 Preset Single Register Packet Structure
Preset Register Request Packet Preset Register Response Packet
Slave Address (1 byte) Slave Address (1 byte)
06 (Function code) (1 byte) 06 (Function code) (1 byte)
Register (2 bytes) Register (2 byte)
Data (2 bytes) Data (2 bytes)
CRC Checksum (2 bytes) CRC Checksum (2 bytes)
Table 5.8 Preset Multiple Registers Packet Structure
Preset Registers Request Packet Preset Registers Response Packet
Slave Address (1 byte) Slave Address (1 byte)
16 (Function code) (1 byte) 16 (Function code) (1 byte)
Start Register (2 bytes) Start Register (2 bytes)
# of registers to write (2 bytes) # of registers (2 bytes)
Byte Count (1 byte) CRC Checksum (2 bytes)
Data (2 bytes)
…
…
CRC Checksum (2 bytes)