问题描述：
M340的Modbus端口在用READ_VAR和WRITE_VAR指令时，分别支持什么Modbus功能代码？相同的指令在Quantum和Premium中呢？所属产品线：
Modicon Quantum解决方法：
READ_VAR和WRITE_VAR在M340中支持的Modbus功能代码为:
| Modbus request | Function code | Communication function |
| Read bits | 16#01 or 16#02 | READ_VAR |
| Read words | 16#03 or 16#04 | READ_VAR |
| Write bits | 16#0F | WRITE_VAR |
| Write words | 16#10 | WRITE_VAR |
READ_VAR和WRITE_VAR在Premium中支持的Modbus功能代码为:
| Modbus request | Function code | Communication function |
| Read bits | 16#01 | READ_VAR |
| Read words | 16#03 | READ_VAR |
| Write one or n bits | 16#05 or 16#0F | WRITE_VAR |
| Write one or n words | 16#06 or 16#10 | WRITE_VAR |
| Read input bits* | 16#02 | SEND_REQ |
| Read input words* | 16#04 | SEND_REQ |
| *except on Terminal port | ||
Quantum中的XXMIT支持的Modbus功能代码为：
| Function Code | Master PLC Data Area | Slave PLC Data Area |
| 03 (Read multiple 4x) | %MW (destination) | %MW (source) |
| 04 (Read multiple 3x) | %MW (destination) | %IW (source) |
| 01 (Read multiple 0x) | %M (destination) | %Q (source) |
| 02 (Read multiple 1x) | %M (destination) | %I (source) |
| 16 (Write multiple 4x) | %MW (source) | %MW (destination) |
| 15 (Write multiple 0x) | %M (source) | %Q (destination) |
| 05 (Write single 0x) | %M (source) | %Q (destination) |
| 06 (Write single 4x) | %MW (source) | %MW (destination) |
是否有帮助？
