[Introduction]:The distributed IO expansion module adopts an scalable design in structure and needs to be used with our M31 series distributed IO host.
| Symbol | Name | Function/ Description |
| DOI | DOI switch output | DOI switching output interface, used in conjunction with COM1 |
| COM1 | COM terminal of DOI | COM terminal of DOI |
| DO2 | DO2 switch output | DO2 switch output interface, used in conjunction with COM2 |
| COM2 | COM terminal of DO2 | COM terminal of DO2 |
| DO3 | DO3 switch output | DO3 switching output interface, used in conjunction with COM3 |
| COM3 | COM terminal of DO3 | COM terminal of DO3 |
| DO4 | DO4 switch output | DO4 switching output interface, used in conjunction with COM4 |
| COM4 | COM terminal of DO4 | COM terminal of DO4 |
| DO5 | DO5 switch output | DO5 switching output interface, used in conjunction with COM5 |
| COM5 | COM terminal of DO5 | COM terminal of DO5 |
| DO6 | DO6 switch output | DO6 switching output interface, used in conjunction with COM6 |
| COM6 | COM terminal of DO6 | COM terminal of DO6 |
| DO7 | DO7 switch output | DO7 switching output interface, used in conjunction with COM7 |
| COM7 | COM terminal of DO7 | COM terminal of DO7 |
| DO8 | DO8 switch output | DO8 switching output interface, used in conjunction with COM8 |
| COM8 | COM terminal of DO8 | COM terminal of DO8 |
| VO+ | Power output positive pole | The positive pole of the power supply output is the same as the power supply voltage of the device. |
| VO+ | Power output positive pole | The positive pole of the power supply output is the same as the power supply voltage of the device. |
| VO- | Power output negative pole | The negative pole of the power supply output is the same as the power supply voltage of the device. |