Telemetry Data Storage On The Disk - Safran CORTEX CRT Quantum User Manual

3.3.14. Telemetry Data Storage on the Disk

To each telemetry channel (up to 8 channels are available for low-rate applications) is allocated a storage area
on the disk organized as a FIFO structure. Modification of the storage capacity (maximum number of files and file
size) is by system parameters and requires restarting the CORTEX CRT Quantum.
Telemetry frames or blocks of raw data (or dummy frames if the telemetry chain is unlocked) are stored on the
disk (default files: c:\Program Files\In-snec\crtxnt\Tmui\Ftmuj, where i = telemetry chain number [a to h] and j = 1
to N, N being the number of files in the storage area) under the form of telemetry messages as specified in
Annex 1 (see Section 2.4). Telemetry data are binary-coded. The file name and access path can be changed in
the Windows registry.
Note: storage of dummy telemetry frames or blocks can be disabled in the Windows registry (see section
4.2.8.3).
Example: store 24 hours of telemetry data (one data stream only), 2048 bps, 256-byte minor frames:
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Telemetry storage can be activated/inhibited by a Control Client. Once the storage function has been activated,
the following commands are available:
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The identifier of the current file as well as the position of the write pointer in the file, is available in each TMU
monitoring table.
The « stop writing » conditions are:
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The file FTMU in each TMU repository (C:\Program Files\In-Snec\crtxnt\TMUx, x= A..H) contains information
about the records FTMUn, n=1..N.
While FTMU is an ASCII file, it should not be modified by any other mean than the signal processing software
provided with Cortex units. For consistency, FTMUn files should not be deleted/modified either, except in the
case of a full cleanup of the repository.
The FTMU file contains an entry for each FTMUn files in the same repository, as in the example below:
1 5 0087653b:000467d2 00878ed5:000f14ed 19000 0
2 5 00878ed6:000177bd 0087b870:000c24d9 19000 0
3 5 0087b870:000dc9e8 0087e20b:000934c4 19000 0
4 5 0087e20b:000ad9d5 00880ba6:000644b2 19000 0
© Safran Data Systems
COMMAND RANGING & TELEMETRY UNIT CORTEX
CRT QUANTUM USER'S MANUAL
Telemetry packet size:
Minor frame duration:
Required storage size:
Select the first file to write (1 is the identifier of the first file in the storage area),
Program the « stop writing » conditions (see below),
Start writing data to the selected file,
Stop writing data,
Resume writing data, from the current position in the storage area.
Stop on reception of a « Stop writing » command,
Stop when the programmed number of files has been written. This number of files is less or
equal to the number of files of the storage area.
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64 bytes (TCP-IP header, time-tag, miscellaneous status)
256 bytes (TM data)
4 bytes (TCP-IP postamble)
Total: 324 bytes
(8 x 256): 2048 = 1 second
24 x 3600 = 86,400 frames ≈ 28 Mbytes
Safran Data Systems
.
Ref. DTU 100042
Is.Rev. 5.17
Date: Dec.
03, 2021Sept. 30, 2021
Page 101