MIL-STD-1553

Complete Online Resource

Notice I

1.0 Military Standard

MIL-STD-1553B
NOTICE 1(USAF)
12 February 1980

MILITARY STANDARD

AIRCRAFT INTERNAL TIME DIVISION
COMMAND/RESPONSE MULTIPLEX DATA BUS

TO ALL HOLDERS OF MIL-STD-1553B.

  1. THE FOLLOWING PAGES OF MIL-STD-1553B HAVE BEEN REVISED AND SUPERSEDE THE PAGES LISTED:
    New Page Superseded Page
    Date
    iii
    iii
    		 21 September 1978
    viii
    viii
    		 21 September 1978
    34
    34
    		 21 September 1978
  2. THE FOLLOWING NEW PAGES ARE TO BE INSERTED AS LISTED:
    New Page
    viiia
    35
  3. RETAIN THIS NOTICE PAGE AND INSERT BEFORE THE TABLE OF CONTENTS.
  4. Holders of MIL-STD-1553B will verify that page changes indicated above have been entered. The notice page will be retained as a check sheet. This issuance, together with appended pages, is a separate publication. Each notice is to be retained by stocking points until the Military Standard is completely revised or cancelled.
  5. This notice is applicable to all U.S. Air Force internal avionics activities.

Custodian: Preparing activity
Air Force – 11 Air Force – 11

Project MISC-FD32

*U.S.GOVERNMENT PRINTING OFFICE: 1980-603-121/1244 FSC MISC

2.0 Forward

This standard contains requirements for aircraft internal time division command/response multiplex data bus techniques which will be utilized in systems integration of aircraft subsystems. Even with the use of this standard, subtle differences will exist between multiplex data buses used on different aircraft due to particular aircraft mission requirements and the designer options allowed in this standard. The system designer must recognize this fact, and design the multiplex bus controller hardware and software to accommodate such differences. These designer selected options must exist, so as to allow the necessary flexibility in the design of specific multiplex systems in order to provide for the control mechanism, architecture redundancy, degradation concept and traffic patterns peculiar to the specific aircraft mission requirements. * Appendix Section 20 selects those options which shall be required and further restricts certain portions of the standard for use in Air Force aircraft internal avionics applications.

Supersedes page iii of 21 September 1978

3.0 Content

Paragraph or Figure
FIGURES
Spec Page
 Web Page Section Number
1 Sample Multiplex Data Bus Architecture
2
 Review and Rationale of
MIL-STD-1553 A and B		 2.1
2 Data Encoding
5
 Review and Rationale of
MIL-STD-1553 A and B		 4.3.3.2
3 Word Formats
6
 Review and Rationale of
MIL-STD-1553 A and B		 4.3.3.4
4 Command and Status Sync
7
 Review and Rationale of
MIL-STD-1553 A and B		 4.3.3.5.1.2
5 Data Sync
7
 Review and Rationale of
MIL-STD-1553 A and B		 4.3.3.5.2.1
6 Information Transfer Formats
15
 Review and Rationale of
MIL-STD-1553 A and B		 4.3.3.6
7 Broadcast Information Transfer Formats
16
 Review and Rationale of
MIL-STD-1553 A and B		 4.3.3.6
8 Intermessage Gap and Response Time
18
 Review and Rationale of
MIL-STD-1553 A and B		 4.3.3.8
9 Data Bus Interface Using Transfomer Coupling
19
 Review and Rationale of
MIL-STD-1553 A and B		 4.3.3.8
10 Data Bus Interface Using Direct Coupling
20
 Review and Rationale of
MIL-STD-1553 A and B		 4.3.3.9
11 Coupling Transformer
24
 Review and Rationale of
MIL-STD-1553 A and B		 4.5.1.5.1.1.2
12 Terminal I/O Characteristics for Transformer Coupled and Direct Coupled Stubs
24
 Review and Rationale of
MIL-STD-1553 A and B		 4.5.2.1.1.2
13 Output Waveform
26
 Review and Rationale of
MIL-STD-1553 A and B		 4.5.2.1.2.4
TABLES
I Assigned Mode Codes
10
 Review and Rationale of
MIL-STD-1553 A and B		 4.3.3.5.1.7
II Criteria for Acceptance or Rejection of a Terminal for the Noise Rejection Test
28
 Review and Rationale of
MIL-STD-1553 A and B		 4.5.2.1.2.4
APPENDIX
10 General
31
 Review and Rationale of
MIL-STD-1553 A and B		 5.1
10.1 Redundancy
31
 Review and Rationale of
MIL-STD-1553 A and B		 5.2
10.2 Bus Controller
31
 Review and Rationale of
MIL-STD-1553 A and B		 5.3
10.3 Multiplex Selection Criteria
33
 Review and Rationale of
MIL-STD-1553 A and B		 5.4
10.4 High Reliability Requirements
33
 Review and Rationale of
MIL-STD-1553 A and B		 5.5
10.5 Stubbing
33
 Review and Rationale of
MIL-STD-1553 A and B		 5.6
10.6 Use of Broadcast Option
34
 Review and Rationale of
MIL-STD-1553 A and B		 5.7
20 General
34
 Notice I 3 20
20.1 Mode Codes
34
 Notice I 3 20.1
20.2 Broadcast Command
34
 Notice I 3 20.2
20.3 Mode Code Indicators
34
 Notice I 3 20.3
20.3.1 Bus Controllers
34
 Notice I 3 20.3.1
20.3.2 Remote Terminals
34
 Notice I 3 20.3.2
20.4 Data Bus Cable
35
 Notice I 3 20.4
20.4.1 Shielding
35
 Notice I 3 20.4.1
20.4.2 Characteristic Impedance
35
 Notice I 3 20.4.2
20.5 Cable Coupling
35
 Notice I 3 20.5
20.6 Direct Coupled Stubs
34
 Notice I 3 20.6
20.7 Redundant Data Bus Requirements
35
 Notice I 3 20.7
20.8 Design Consideration
35
 Notice I 3 20.8
APPENDIX FIGURES
20.8.1 Mode Code Indicator
35
 N/A N/A
20.8.2 Clock Stability
35
 N/A N/A
20.8.3 Response Time
35
 N/A N/A
10.1 Illustration of Possible Redundancy
32
 Review and Rationale of
MIL-STD-1553 A and B		 5.2
10.2 Illustration of Possible Redundancy
32
 Review and Rationale of
MIL-STD-1553 A and B		 5.2

Supersedes page viii of 21 September 1978

10.6 Use of broadcast option. The use of a broadcast message as defined in 4.3.3.6.7 of this standard represents a significant departure from the basic philosophy of this standard in that it is a message format which does not provide positive closed-loop control of bus traffic. The system designer is strongly encouraged to solve any design problems through the use of the three basic message formats without resorting to use of the broadcast. If system designers do choose to use the broadcast command, they should carefully consider the potential effects of a missed broadcast message, and the subsequent implications for fault or error recovery design in the remote terminals and bus controllers.

*20. General. This appendix is applicable to all U.s. Air Force aircraft internal avionics activities. The intent of the appendix is to select those options which shall be required and to further restrict certain portions of the standard for use in Air Force avionics. References in parenthesis are to the paragraphs in the standard that are affected.

*20.1 Mode codes. (4.3.3.5.1.7) The mode cotes for dynamic bus control, inhibit terminal flag bit, override inhibit terminal flag bit, selected transmitter shutdown and override selected transmitter shutdown shall not be transmitted on the data bus by bus controllers in Air Force avionics applications. However, these mode codes may be implemented in a remote terminal for Air Force avionics applications.

*20.2 Broadcast command. (4.3.3.6.7) The broadcast command shall not be transmitted on the data bus by bus controllers in Air Force avionics applications. However, this message format may be implemented in remote terminals. If the broadcast message format is implemented in a remote terminal, then that terminal shall also implement the transmit status word mode code as specified in 4.3.3.5.1.7.3. Note that the remote terminal address of 11111 is still reserved for broadcast, and shall not be used for any other purpose in Air Force Avionics applications.

*20.3 Mode code indicators.

*20.3.1 Bus controllers. (4.4.2) In Air Force avionics applications, the bus controller shall be able to utilize both 00000 and 11111 in the subaddress/mode field as defined in 4.3.3.5.1.7. In addition, if a bus controller is required to utilize any mode code in its operation, then it shall be required to implement the capacity to utilize all mode codes.

*20.3.2 Remote terminals. (4.4.3.1) All RT’s which are designed for Air Force avionics applications, and which implement mode codes, shall respond properly to a mode code command, as defined in 4.3.3.5.1.7, with 00000 in the subaddress/mode field. In addition, such RT’s may also respond to 11111 in the subaddress/mode field as a designer option. See section 20.8.1 for design consideration relating to the 11111 mode code indicator.

Supersedes page 34 of 21 September 1978

*20.4 Data bus cable.

*20.4.1 Shielding. (4.5.1.1) The cable shield shall provide a minimum of 90.0 percent coverage.

*20.4.2 Characteristic impedance. (4.5.1.2) The actual (not nominal) characteristic impedance shall be within the range of 70.0 Ohms to 85.0 Ohms at a sinusoidal frequency of 1.0 megahertz (MHz)

*20.5 Cable coupling. (4.5.1.5.1.3) For Air Force avionics applications, the continuous shielding shall provide a minimum of 90.0 percent coverage.

*20.6 Direct coupled stubs. (4.5.1.5.2) Direct coupled studs shall not be utilized in Air Force avionics applications. .

*20.7 Redundant data bus requirements. (4.6) Dual standby redundant data buses as defined in 4.6.3 shall be utilized. There may be more than two data buses utilized but the buses must operate in dual redundant data bus pairs. 4.6.1 and 4.6.2 shall also apply.

*20.8 Design considerations. Avionics designed for Air Forces applications may be required to interface to existing avionics systems which were designed to preceding versions of the standard (e.g., the F-16 avionics suite). In this case, downward compatibility problems between the new avionics and the existing system can be minimized through the consideration of three key items:

*20.8.1 Mode code indicator. In some existing systems, such as the F-16, the bus controller uses 11111 to indicate a mode code command. The designer may wish to implement the capability in the new avionics to respond to 11111 mode code commands, in addition to the required capability for 00000 mode code commands.

*20.8.2 Clock stability. Since this version of the standard relaxed the transmission bit rate stability requirements (4.3.3.3), the avionics designer may wish to return to the stability requirements of the preceding version of the standard. The previous requirements were +0.01 percent long term and +0.001 percent short term stability.

*20.8.3 Response time. This version of the standard also expanded the maximum response time to 12.0 microseconds (4.3.3.8). The designer may also wish to return to the previous maximum response time of 7.0 microseconds as defined in 4.3.3.8 of this version of the standard.

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