MIL-STD-1553, is a published technical standard that defines the mechanical, electrical, and functional characteristics of a serial data bus. It features a dual redundant balanced line physical layer, a (differential) network interface, time division multiplexing, half-duplex command/response protocol, and up to 31 or 32 remote terminals depending on the version (1553B or 1553A).

MIL-STD-1553 is a military standard created in the early 1970s that defines the concept of operation and information flow on a multiplexed data bus, and the electrical and functional formats to be employed. The data bus is used to transfer command/response messages between multiple terminals. It may interconnect up to 31 or 32 Remote Terminals (RT), multiple Bus Monitors (BM) and a Bus Controller (BC). In a typical system, a dual redundant bus is used. Usually, only the primary bus (Bus A) is used to transfer messages; however, the secondary bus (Bus B) may also be used to perform a transfer. If a transfer fails on one bus, retry options allow the transmitter to try the transmission again on the same bus or on the alternate bus. Transmission on the bus occurs serially at 1Mbps. It uses a command/response protocol that transfers a maximum of 32 data words per message with each data word containing 20 bits. The message transmitted on the data bus follows one of these formats: BC to RT, RT to BC or RT to RT. Broadcast transmission is also available with 1553B, address 31 is reserved for that functionality.