Tektronix WFM

From sigrok
(Redirected from File format:Tektronix wfm)
Jump to: navigation, search

The Tektronix WFM format is a special format used by the Tektronix TDS series scopes. It uses less space than the CSV/Matlab export functions provided.

Header

Bytes Field
0 - 1 Magic bytes
2 - 5 Format code
6 Length of data, unsigned integer (so far always 4)
7 - 11 Number of bytes following
12 - 15 Another magic
16-20 Length of header + data (big endian, signed integer)
21 - 28 Vertical position (double)
29 - 36 Horizontal position (double)
37 - 43 Vertical zoom (double)
44 - 51 Horizontal zoom (double)
52 - 53 Acquisition mode (signed integer, currently unknown)
54 - 55 Min max (unknown)
56 - 63 Duration in seconds (double)
63 - 64 Vertical coupling (signed integer)
65 - 66 Horizontal unit (signed integer)
67 - 74 Horizontal time per point (double)
75 - 76 Vertical unit (signed integer)
77 - 84 Vertical offset (double)
85 - 92 Vertical position (double)
93 - 100 Vertical gain (double)
101 - 105 Record length (unsigned integer)
106 - 107 Trigger position (signed integer), possibly in points
108 - 109 Header version (signed integer)
110 - 111 Sampling density (??) (signed integer)
112 - 113 Burst segment length (signed integer)
114 - 115 Waveform source (signed integer)
116 - 121 3x Video 1 (signed integer)
122 - 129 Video 2 (double)
130 - 131 Video 3 (signed integer)
131 - 163 Preamble (???)

Data

Waveform data. Length of this segment is stored in Record length.

To reconstruct the waveform use the following:

y = data[i] * vertgain / 25 / 256 + vertoffset - vertposition * vertgain
x = (i - (reclength*trigpos/100)) * horizscaleperpoint