楼主不会自己查说明吗？

说明里面说得很清楚的，只不过是英文。

AddrFld    WordArr5  

WordArr5 分三种情况：

Elementary description for WordArr5 in Modbus Plus
Elementary description for WordArr5 in Modbus Plus:                    Element Data type Meaning
WordArr5[1] WORD Low value byte:Routing register 1 is used for address specification (routing path addresses one of five) of the destination node during network transfer.The last byte in the routing path that is not zero is the destination node.High value byte:Slot of the network adapter module (NOM), if any (only Quantum).
WordArr5[2] WORD Routing register 2
WordArr5[3] WORD Routing register 3
WordArr5[4] WORD Routing register 4
WordArr5[5] WORD Routing register 5

Elementary description for WordArr5 with TCP/IP EtherNet
Elementary description for WordArr5 with TCP/IP EtherNet                  Element Data type Meaning
WordArr5[1] WORD Low value byte: MBP on Ethernet Transporter (MET) mapping indexHigh value byte:Slot of the NOE module
WordArr5[2] WORD Byte 4 (MSB) of the 32-bit destination IP address
WordArr5[3] WORD Byte 3 of the 32-bit destination IP address
WordArr5[4] WORD Byte 2 of the 32-bit destination IP address
WordArr5[5] WORD Byte 1 (LSB) of the 32-bit destination IP address

Elementary description for WordArr5 with SYMAX EtherNet
Elementary description for WordArr5 with SYMAX EtherNet                     Element Data type Meaning
WordArr5[1] WORD Low value byte:MBP on Ethernet Transporter (MET) mapping indexHigh value byte:Slot of the NOE module
WordArr5[2] WORD Destination drop number (or set to FF hex)
WordArr5[3] WORD Terminator (set to FF hex)
WordArr5[4] WORD No significance
WordArr5[5] WORD No significance

关键是CWRITE_REG、CREAD_REG的管脚具体怎么定义，能否带程序说明下，因为实验过，通讯不成功