10 KiB
Fileformat
A data file of IMC Bus Format type with extension .raw is a mixed text/binary
file featuring a set of markers (keys) that indicate the start of various blocks
of data providing meta information and the actual measurement data. Every single
marker is introduced by character "|" = 0x 7c followed by two uppercase letters,
which characterize the type of marker. Each block is further divided into several
parameters separated by commata "," = 0x 2c and terminated by a semicolon
";" = 0x 3b. For instance, the header - first 600 bytes - of a raw file may
look like this (in UTF-8 encoding)
|CF,2,1,1;|CK,1,3,1,1;
|NO,1,86,0,78,imc STUDIO 5.0 R10 (04.08.2017)@imc DEVICES 2.9R7 (25.7.2017)@imcDev__15190567,0,;
|CG,1,5,1,1,1; |CD,2, 63, 5.0000000000000001E-03,1,1,s,0,0,0, 0.0000000000000000E+00,1;
|NT,1,16,1,1,1980,0,0,0.0; |CC,1,3,1,1;|CP,1,16,1,4,7,32,0,0,1,0;
|CR,1,60,0, 1.0000000000000000E+00, 0.0000000000000000E+00,1,4,mbar;|CN,1,27,0,0,0,15,pressure_Vacuum,0,;
|Cb,1, 117,1,0, 1, 1, 0, 9608, 0, 9608,1, 2.0440300000000000E+03, 1.2416717060000000E+09,;
|CS,1, 9619, 1,<2C>oD <09>nD6<44>nD)<29>nD<6E>
where line breaks where introduced for readability. Most of the markers introduce
blocks of text, while only the last one identified by |CS contains binary data.
The format supports the storage of multiple data sets (channels) in a single
file. The channels may be ordered in multiplex mode (ordering w.r.t. time) or
block mode (ordering w.r.t. to channels).
Markers
The markers (keys) are introduced by "|" = 0x 7c followed by two uppercase
letters. There are two types of markers distinguished by the first letter:
- critical markers: introduced by
|Cfeaturing uppercaseC - noncritical markers: introduced by
|Nfeaturing uppercaseN
The second letter represents further details of the specific key. Note, that
while the noncritical keys are optional, any .raw file cannot be correctly
decoded if any of the critical markers are misinterpreted, invalid or damaged.
The second uppercase letter is followed by the first comma and the version
of the key starting from 1. After the next comma, an (long) integer (in text
representation) specifies the length of the entire block, i.e. the number of
bytes between the following comma and the block-terminating semicolon. The further
structure of a block is not defined and may feature different numbers of additional
parameters. The format allows for any number of carriage returns (CR = 0x0d)
and line feeds (LF = 0x 0a) between keys, i.e. the block terminating semicolon
and the vertical bar (pipe) of the next key. The following critical markers
are defined
| marker | structure (example) | description |
|---|---|---|
| CF | CF,2,1,1; | format version and processor |
| CK | CK,1,3,1,; | start of group of keys |
| length is always 3 | ||
| must be 0 or 1 depending correct closure of the measurment series | ||
| CB | CB,1,,,,,,; | defines a group of cannels |
| CT | CT,1,,,,,,,,; | text definition |
| CG | CG,1,,,,; | introduces group of components corresponding to CC keys |
| field type is one of: 1 = real number | ||
| 2 = XY | ||
| 3 = 3XY | ||
| 4 = complex with Re + Im | ||
| 5 = complex with Abs + Phase | ||
| 6 = complex: Abs in dB + Phase | ||
| dimension: 1 for fieldtype 1, 2 for fieldtype 2-6 | ||
| CD | CD,1,,,,,,0,0,0; | dx = distance between two samples |
| calibration = 1 : calibrated time-basis | ||
| = 0 : noncalibrated time-basis | ||
| unit: unit of this axis | ||
| CZ | CZ,1,,,,,,,,; | scaling of z-axis for segments |
| CC | CC,1,,,; | start of single component: |
| - componentindex = 1 real, real part, abs | ||
| = 2 complex, imaginar part, phase | ||
| - analogdigital = 1 analog = 2 digital | ||
| CP | CP,1,,,,,,,,,; | buffref = int > 0 corresp.to buffer descript. in Cb key |
| bytes: number of bytes for singel value | ||
| datatype: 1 = unsigned byte, 2 = signed byte, | ||
| 3 = unsigned short, 4 = signed short | ||
| 5 = unsigned long, 6 = signed long | ||
| 7 = float, 8 = double | ||
| 9 = imc Devices transitional recording | ||
| 10 = timestamp ascii, 11 = 2byte word digital | ||
| 13 = 6byte unsigned long | ||
| signbits: number of significant bits | ||
| mask: default = 0 | ||
| offset: offset of first sample in data block | ||
| numsamples: number of subsequent samples in channel | ||
| bytedist: number of bytes between last sample of channel | ||
| to start of next channel | ||
| Cb | Cb,1,,,,,,, | |
| ,,,0,X0,,,,[buffref,...]; | buffer description | |
| CR | ||
| CN | ||
| CS | ||
| CI | ||
| Ca |