之前运行很好，这几天突然发现通讯丢失，查看后发现CP444报故障，
有如下提示
A port interconnection was configured but a single partner was not detected at the port.
Possible causes:
- Non PNIO compliant device connected to this port
- Port interconnection configured but no device connected or partner device turned off, cable defective

Remedies:
- Adapt the cabling of the configured port interconnection
- Adapt the port interconnection in the configuration
求分析，谢谢