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hardware:mark5.datacheck
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hardware:mark5.datacheck [2012/02/03 01:13] Jamie McCallum created |
hardware:mark5.datacheck [2012/02/03 02:00] (current) Jamie McCallum |
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| **Mark5b data format** | **Mark5b data format** | ||
| - | The recorded data consists of "frames", each with a length of 10016 bytes. Each frame consists of a 16-byte header, followed by 10000 bytes of data. The header starts with a sync word (represented as abaddeed in hexadecimal), followed by a frame counter (represented as bead0000, etc) | + | The recorded data consists of frames, each with a length of 10016 bytes. Each frame consists of a 16-byte header, followed by 10000 bytes of data. The header starts with a sync word (represented as abaddeed in hexadecimal), followed by a frame counter (represented as bead0000, etc). This frame counter should start at bead 0000 the count should increment by one at each header. The counter should loop at a count of 3200 (for a data rate of 256 Mbps - this scales as (Data rate)/256 so 512 Mbps loops at a count of 6400). |
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| + | *Checking recorded data* | ||
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| + | Once you have exported a mark5b data file, you can check the data quality on a byte-level use this recipe. | ||
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| + | ''od -Ad -tx4 test_034_011402.mk5b | grep abaddeed | cut -d' ' -f1 > test.byteindex'' | ||
| + | ''od -Ad -tx4 test_034_011402.mk5b | grep abaddeed | cut -d' ' -f3 > test.counter'' | ||
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| + | The output files consist of the byteindex file - this is the list of bytes at which the sync word was found. If the data was exported from the start of a scan, the first byte should be 0 and the index should increment by 10016. You can check this in octave with this recipe. | ||
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| + | ''load test.byteindex;find(diff(test)~=10016)'' | ||
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| + | It should return ''ans = [](0x1)'' if it is incrementing correctly. Please note that abaddeed may occur naturally in the recorded data (although rarely). An inspection of the data around any apparent jump should make this clear. | ||
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| + | You can check that the counter is correctly incrementing using that recipe. | ||
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| + | ''FID=fopen('test.counter');clear C; A=fread(FID,'uint8');B=reshape(A, 9, length(A)/9)';for i=1:length(A)/9; C(i)=sum(hex2dec(char(B(i,1:8))));end;fclose(FID);find(diff(C)~=1 & diff(C)~=-3199)'' | ||
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| + | This recipe should return ''ans = [](0x1)'' if the counter is correctly incrementing. Again, if abaddeed has occurred in the data the counter will apparently jump. | ||
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/home/www/auscope/opswiki/data/attic/hardware/mark5.datacheck.1328231602.txt.gz · Last modified: 2012/02/03 01:13 by Jamie McCallum
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