The MIL-STD-1553 is a military standard published by the United States Department of Defense. This standard defines the electrical, mechanical, and functional characteristics of a serial data bus. It was originally used for military avionics, but is now also commonly used for both military and civil spacecraft on-board data handling subsystems. The standard was established in 1973 and has developed into a widely accepted standard for networking for integrating military platforms. Let’s now take a look at the features and uses of this standard.
Features and Key Elements of the MIL-STD-1553
The standard features multiple dual redundant balanced line physical layers, time division multiplexing, a (differential) network interface, up to 31 remote terminals (devices) and half-duplex command/response protocol. This standard is used to describe modes of communication as well as electrical interface requirements for the subsystems that are connected to the data bus. Key components of the MIL-STD-1553 include:
* Bus controller – provides data flow control for all transmissions on the bus using a command/response method.
* Data bus – internal system that is used to provide transportation of data. The standard defines characteristics for twisted pair shielded cables and notice 2 adds a definition for connector polarity.
* Data bus coupler – isolates the main bus from the terminals, by use of direct coupling or transformer coupling.
* Remote terminal – embedded remote terminal connected to the data bus that contains interface circuitry located in a subsystem or sensor, main job is to transfer data in and out of the subsystem that is controlled by the data bus.
* Bus monitor – listens to all messages from the data bus and collects the data.
Use of the MIL-STD-1553 in the Commercial, Military, and Aerospace Industries
It was originally meant for use with the U.S. Air Force and Navy aircraft. With revisions, this standard now also covers applications for ships, satellites, combat vehicles, as well as the International Space Station Program. MIL-STD-1553 standard also covers a wide range of commercial avionic applications and is widely used by all branches of the military. This standard is supported by a variety of modules such as data bus analyzers, embedded solutions, flight modules as well as test/simulation modules.