SOC-SLP11-E1/PCM interface protector, also known as E1 line undamaged protector, is designed to solve the real-time smoothness of the 2M channel in communication systems, maintain stable and reliable operation of relay protection devices, and prevent damage caused by interruptions or errors in the 2M channel. The E1 line undamaged protector synchronously sends one 2M signal to two 2M channels. The receiving side selects one of the 2M channels for reception, ensuring uninterrupted and error free transmission of the 2M signal under normal reception on any 2M channel. The product developed by our company has high integration, small size, stable performance, resistance to high and low long-term operation, and comes with monitoring function.