## 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,�oD �nD6�nD)�nD� ``` 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,; | 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 | | |