 |
|||
|
|
|||
| ||||||||||
|
|  MIL-D-81347C(AS)
3.5.2.4.2
Navigation Multiplexer
Functional Description - The Navigation Multiplexer (NM) is an
3.5.2.4.2.1
interface unit between the computer and two inertial platforms and doppler navigation equipment.
Figure 60 is a functional flow diagram of the navigation multi-
plexer.
3.5.2.4.2.2-
General Description - The NM shall have the capability of trans-
mitting data bits from the inertial platforms and the doppler navigation equipment to the computer.
Each inertial platform and doppler navigation equipment shall use a single serial line for data to the NM.
3.5.2.4.2.3
Operating Requirements
Data Transfer - A peripheral equipment which communicates with
3.5.2.4.2.3.1
the computer via the NM shall be able to transmit one data word to the computer by following the con-
trol line sequence given below.
(1) The computer requests the information required by using its
Normal Output Function (Output Acknowledge).
(2) The NM generates the select line for that function and starts
the clock.
(3) The peripheral sends the data to the NM using the 22 clock
bits from the NM.
(4) The NM places the data bits from the peripheral equipment
on the computer data lines.
(5) The NM sets the Input Data Request Line to indicate that it
has data ready for transmission to the computer.
(6) The Computer 1/0 Subunit detects the Input Data Request.
(7) The computer samples the data lines, at its convenience.
(8) The computer sets the Input Acknowledge Line indicating that
it has sampled the data.
(9) The NM drops the Input Data Request.
Timing, Priority and Initialization
3.5.2.4.2.3.2
(1) The computer selects the peripheral unit and function to be
transmitted.
(2) The NM shall be self-initializing, i.e. , when power is applied
to the NM, no spurious data shall be transmitted to the computer and the NM shall be ready for normal
operation.
Navigation Word Sampling - Each word shall be sampled at random
3.5.2.4.2.3.2.1
times but not more often than once every 30 milliseconds.
3.5.2.4.2.4
Test Loops
In- Flight Performance Monitoring - The NM shall be capable of
3.5.2.4.2.4.1
loop operation. This loop operation, Computer to NM and NM to computer, shall permit the computer
program to monitor automatically the performance of the NM. The test loops shall be utilized for in-
flight performance monitoring and diagnostic programs.
119
|
|
Privacy Statement - Press Release - Copyright Information. - Contact Us |
Click
here for thousands of PDF manuals