... optical transmission equipment 1. Product OverviewMA20A01/04 2M port protection switch-over equipment was designed and developed by ... management inserting board, and the network management provides Ethernet port outward; MA20A04 is in 19” 1U structure, with ... single AC, single DC, the network management provides RS232 or RS485 port outward. 2. Equipment featuresLow cost, simple use, installation, ...