IMCtermite/doc/Fileformat.md

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## 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:
1. _critical_ markers: introduced by `|C` featuring uppercase `C`
1. _noncritical_ markers: introduced by `|N` featuring uppercase `N`
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,<closed>; | start of group of keys |
| | | length is always 3 |
| | | <closed> must be 0 or 1 depending correct closure of the measurment series |
| CB | CB,1,<length>,<groupindex>,<namelength>,<name>,<commentlength>,<comment>; | defines a group of cannels |
| CT | CT,1,<length>,<groupindex>,<namelength>,<name>,<textlength>,<text>,<commentlength>,<comment>; | text definition |
| CG | CG,1,<length>,<numberofcompontent>,<fieldtype>,<dimension>; | 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,<length>,<dx>,<calibration>,<unitlength>,<unit>,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,<length>,<dz>,<dzcalibration>,<z0>,<z0calibration>,<unitlength>,<unit>,<segmentlength>; | scaling of z-axis for segments |
| CC | CC,1,<length>,<componentindex>,<analogdigital>; | start of single component: |
| | | - componentindex = 1 real, real part, abs |
| | | = 2 complex, imaginar part, phase |
| | | - analogdigital = 1 analog = 2 digital |
| CP | CP,1,<lenght>,<buffref>,<bytes>,<datatype>,<signbits>,<mask>,<offset>,<numsamples>,<bytedist>;| 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,<lenght>,<numbuff>,<bytesinuserinfo>,<buffref>,<indexsamplekey>,<offsetbuffer>, | |
| | <bufferlength>,<offset>,<fillbytes>,0,X0,<addtime>,<userinfo>,<newevent>,[buffref,...]; | buffer description |
| CR | | |
| CN | | |
| CS | |
| CI | | |
| Ca | | |