PDH fiber optical multiplexer with STM-1 rate, two optical interfaces, which constitute 1+1 mode. The equipment can transmit 8E1 simultaneously, 1 channel 100M Ethernet and 1 NX64K V. 35. It has a perect alarm function, it is easy to maintain the daily network. Moreover With high-integrated design and low power advanced technology, this equipment runs with its superior quality and reliable performance. KEY FEATURE 1. 1+1 optical interfaces, protection, switching without traffic affection 2. The LCD is on the front panel, with the help of the buttons you can operate the network both local and remote equipment. Another way is to manage by the PC. 3. The equipment has both external alarm input circuit and external alarm output circuit. Output device is relay. 4. The power supply can both AC220V and DC-48V, and it is available for AC and DC inputs feeding simultaneously which can work with 1+1 protection. 5. The optical card is stable, and the network is through COM, and the sub-rack is gray.