MIL STD 1553B

This library implements a complete set of Rust structs for parsing or constructing messages that comply with the MIL STD 1553B communication protocal.

Features

The following features make this library useable in constrained embedded systems for government, commercial, or military projects that can't have virally licensed dependencies.

• Does not use the standard library (no_std)
• Does not allocate dynamic memory
• Has no dependencies *
• MIT licensed

* No runtime dependencies. If you use the derive feature flag, you will have to build proc-macro dependencies, but these are built and used on the host, not on the target system.

Basic usage

Creating a message

A message can be built using the constructor methods of Message, CommandWord, StatusWord, and DataWord.

    use mil_std_1553b::*;

    let message = Message::<3>::new()
        .with_command(CommandWord::new()
            .with_address(Address::Value(12))
            .with_subaddress(SubAddress::Value(5))
            .with_word_count(2)
            .build().unwrap()
        )
        .with_data(DataWord::new())
        .with_data(DataWord::new())
        .build()
        .unwrap();

    assert_eq!(message.length(),3);

Parsing a message

Command messages

Messages can be parsed as command messages, and the leading command word will determine how many data words will be parsed from the buffer.

    use mil_std_1553b::*;

    let message: Message = Message::read_command(&[
        0b10000011, 
        0b00001100, 
        0b00100010, 
        0b11010000, 
        0b11010010
    ])
    .unwrap();

    assert_eq!(message.length(),2);

Status messages

    use mil_std_1553b::*;

    let message: Message = Message::read_status(&[
        0b10000011, 
        0b00001100, 
        0b01000010, 
        0b11010000, 
        0b11010010
    ])
    .unwrap();

    assert_eq!(message.length(), 2);

Parsing a word

Words can be parsed from two-byte byte arrays or u16s. Data words can also be created from strings.

    use mil_std_1553b::*;

    let word = DataWord::new()
        .with_bytes([0b01001000, 0b01001001])
        .with_calculated_parity()
        .build()
        .unwrap();

    assert_eq!(word.as_string(),Ok("HI"));

Roadmap

• Words implemented
  • Command, Status, and Data words created
  • Words can be parsed from binary
  • Words can be converted into binary
  • Words have parsing tests
  • Words have conversion tests
  • Documentation exists for words
• Messages implemented
  • Message struct is created
  • Messages can be constructed from words
  • Messages can be parsed from binary
  • Messages have parsing tests
  • Messages have conversion tests
  • Documentation exists for messages
• Conveniance, standardization, documentation
  • Derive/macro creation of custom words for a message
  • Small fixes for enum and flag standardization
  • Fully documented code base
  • Maximum lints enforced and no unsafe code
• Integration tests implemented
  • CI/CD pipelines building for all host -> cross compile targets
  • Round-trip tests (binary -> struct -> binary) exist for messages
  • Round-trip tests (binary -> struct -> binary) exist for words
• Message pattern constructors designed
• Directed pattern constructors implemented
  • BC - RT pattern implemented
  • BC - RT pattern tests implemented
  • RT - BC pattern implemented
  • RT - BC pattern tests implemented
  • RT - RT pattern implemented
  • RT - RT pattern tests implemented
  • Mode W/O Data (T) pattern implemented
  • Mode W/O Data (T) pattern tests implemented
  • Mode With Data (T) pattern implemented
  • Mode With Data (T) pattern tests implemented
  • Mode With Data (R) pattern implemented
  • Mode With Data (R) pattern tests implemented
• Broadcast pattern constructors implemented
  • BC - RT pattern implemented
  • BC - RT pattern tests implemented
  • RT - RT pattern implemented
  • RT - RT pattern tests implemented
  • Mode W/O Data pattern implemented
  • Mode W/O Data pattern tests implemented
  • Mode With Data pattern implemented
  • Mode With Data pattern tests implemented

Notes

Words

A "word" in the 1553B standard is made up of twenty bits, total. Three sync bits, 16 bits of data (in one of three different formats), and a trailing parity bit ¹. This means that there are two ways of referencing a particular bit- either with a bit index offset from the beginning of the word data or as a "bit time" offset from the beginning of the word, including the sync bits.

Index	Sync1	Sync2	Sync3	0	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	Parity
Time	-	-	-	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	-
Offset	-	-	-	0	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	-

The bit-time reference is used in the standard, but because we're only dealing with the 16-bit data from each word in this project we'll be using a zero-indexed reference in the actual code.

Footnotes

1. https://www.milstd1553.com/wp-content/uploads/2012/12/MIL-STD-1553B.pdf ↩