The frequency changing relay is out of order. It can not change frequencies.

频率转换继电器故障，不能转换频率。

youdao

This paper introduces the autocontrolling system composed with proximity sensor and PLC, this system is instead of relay controlling complicated system to realize cylinder changing automatically.

本文介绍接近开关传感器与PLC的控制相连接而组成的自动控制系统，它取代操作繁琐的电器继电器控制系统，实现造纸圆筒换卷过程的自动控制。

youdao

These devices should just relay data rather than changing it and the argument against having intermediary nodes doing things like modifying web pages is that this can, at the least, introduce performance and reliability problems.

FORBES: Cox Inserts User Notification Popups By Hijacking Web Pages, Doesn't Tell Support, Invites Problems