Mercurial > pygpibtoolkit / file comparison
comparison: HP3562A/trace_decoder.py
HP3562A/trace_decoder.py
- changeset 14
- 07e2cbf140df
- parent 11
- 3ccb0023cf41
- child 16
- de9122b5680a
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| 13:78e3e839658b | 14:07e2cbf140df |
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| 1 # -*- coding: utf-8 -*- | |
| 2 """ | |
| 3 trace_decoder | |
| 4 ============= | |
| 5 | |
| 6 Module for decoding a trace generated by the HP3562A DSA, using the | |
| 7 GPIB command "DDBN" (Dump Data BiNary). | |
| 8 | |
| 9 This file can be exectued as a python script. Use '-h' for more informations. | |
| 10 """ | |
| 11 import struct | |
| 12 import numpy | |
| 13 from HP3562A import format_header, decode_float, decode_string, decode_header | |
| 14 from HP3562A.enum_types import * | |
| 15 | |
| 16 | |
| 17 HEADER = [ ("Display function", EDSP, 'h', 2), | |
| 18 ('Number of elements', int, 'h', 2), | |
| 19 ('Displayed elements', int, 'h', 2), | |
| 20 ('Number of averages', int, 'h', 2), | |
| 21 ('Channel selection', ECH, 'h', 2), | |
| 22 ('Overflow status', EOVR, 'h', 2), | |
| 23 ('Overlap percentage', int, 'h', 2), | |
| 24 ('Domain', EDOM, 'h', 2), | |
| 25 ('Volts peak/rms', EVLT, 'h', 2), | |
| 26 ('Amplitude units', EAMP, 'h', 2), | |
| 27 ('X axis units', EXAXIS, 'h', 2), | |
| 28 ('Auto math label', str, 's', 14), | |
| 29 ('Trace label', str, 's', 22), | |
| 30 ('EU label 1', str, 's', 6), | |
| 31 ('EU label 2', str, 's', 6), | |
| 32 ('Float/Interger', bool, 'h', 2), | |
| 33 ('Complex/Real', bool, 'h', 2), | |
| 34 ('Live/Recalled', bool, 'h', 2), | |
| 35 ('Math result', bool, 'h', 2), | |
| 36 ('Real/Complex input', bool, 'h', 2), | |
| 37 ('Log/Linear data', bool, 'h', 2), | |
| 38 ('Auto math', bool, 'h', 2), | |
| 39 ('Real time status', bool, 'h', 2), | |
| 40 ('Measurement mode', EMEAS, 'h', 2), | |
| 41 ('Window', EWIN, 'h', 2), | |
| 42 ('Demod type channel 1', EDEMOD, 'h', 2), | |
| 43 ('Demod type channel 2', EDEMOD, 'h', 2), | |
| 44 ('Demod active channel 1', bool, 'h', 2), | |
| 45 ('Demod active channel 2', bool, 'h', 2), | |
| 46 ('Average status', EAVG, 'h', 2), | |
| 47 ('Not used', int, 'hh', 4), | |
| 48 ('Samp freq/2 (real)', decode_float, None, 4), | |
| 49 ('Samp freq/2 (imag)', decode_float, None, 4), | |
| 50 ('Not used', decode_float, None, 4), | |
| 51 ('Delta X-axis', decode_float, None, 4), | |
| 52 ('Max range', decode_float, None, 4), | |
| 53 ('Start time value', decode_float, None, 4), | |
| 54 ('Expon wind const 1', decode_float, None, 4), | |
| 55 ('Expon wind const 2', decode_float, None, 4), | |
| 56 ('EU value chan 1', decode_float, None, 4), | |
| 57 ('EU value chan 2', decode_float, None, 4), | |
| 58 ('Trig delay chan 1', decode_float, None, 4), | |
| 59 ('Trig delay chan 2', decode_float, None, 4), | |
| 60 ('Start freq value', decode_float, None, 8), | |
| 61 ('Start data value', decode_float, None, 8), | |
| 62 ] | |
| 63 | |
| 64 def decode_trace(data): | |
| 65 """ | |
| 66 Decode the data (as generated by the HP3562A DSA in response to a | |
| 67 "DDBN" command), and returns a couple (header, values). | |
| 68 | |
| 69 header is the dictionnary of the header of the dumped data block, | |
| 70 value is a numpy array holding the trace (vector of float or | |
| 71 complex values). | |
| 72 """ | |
| 73 header, idx = decode_header(data, HEADER) | |
| 74 resu = [] | |
| 75 for i in range(header["Number of elements"]): | |
| 76 resu.append(decode_float(data[idx: idx+4])) | |
| 77 idx += 4 | |
| 78 return header, numpy.array(resu, dtype=float) | |
| 79 | |
| 80 | |
| 81 | |
| 82 def main(): | |
| 83 import sys | |
| 84 import optparse | |
| 85 opt = optparse.OptionParser("A simple tool for tracing a dumped trace") | |
| 86 opt.add_option('-f', '--filename', default=None, | |
| 87 dest='filename', | |
| 88 help='Output filename. If not set, read from stdin') | |
| 89 opt.add_option('-m', '--mode', default='binary', | |
| 90 dest='mode', | |
| 91 help='Dumping mode (may be "binary" [default], "ascii" or "ansi")', | |
| 92 ) | |
| 93 opt.add_option('-d', '--display-header', default=False, | |
| 94 action="store_true", | |
| 95 dest="displayheader", | |
| 96 help="Display the trace header") | |
| 97 opt.add_option('-P', '--noplot-trace', default=True, | |
| 98 action="store_false", | |
| 99 dest="plot", | |
| 100 help="Do not display the plot of the trace") | |
| 101 opt.add_option('-x', '--xmode', default='lin', | |
| 102 dest='xmode', | |
| 103 help='X coordinate mode (may be "lin" [default] or "log")') | |
| 104 opt.add_option('-y', '--ymode', default='lin', | |
| 105 dest='ymode', | |
| 106 help='Y coordinate mode (may be "lin" [default], "log" or "db")') | |
| 107 | |
| 108 options, argv = opt.parse_args(sys.argv) | |
| 109 | |
| 110 | |
| 111 if options.filename is None: | |
| 112 print "Can't deal stdin for now..." | |
| 113 sys.exit(1) | |
| 114 try: | |
| 115 header, data = decode_trace(open(options.filename, 'rb').read()) | |
| 116 except Exception, e: | |
| 117 print "ERROR: can't read %s an interpret it as a HP3562 trace"%options.filename | |
| 118 print e | |
| 119 sys.exit(1) | |
| 120 | |
| 121 if options.displayheader: | |
| 122 print format_header(header, HEADER, 100) | |
| 123 if options.plot: | |
| 124 f0 = header['Start freq value'] | |
| 125 dx = header['Delta X-axis'] | |
| 126 n = header['Number of elements'] | |
| 127 x = numpy.linspace(f0, f0+dx*n, len(data)) | |
| 128 y = data.copy() | |
| 129 | |
| 130 import pylab | |
| 131 if options.ymode != "lin": | |
| 132 minv = min(y[y>0]) | |
| 133 y[y==0] = minv | |
| 134 y = numpy.log10(y) | |
| 135 if options.ymode == "db": | |
| 136 y = y*10 | |
| 137 pylab.ylabel('db') | |
| 138 pylab.grid() | |
| 139 pylab.plot(x, y) | |
| 140 pylab.xlabel('frequency') | |
| 141 pylab.show() | |
| 142 | |
| 143 | |
| 144 if __name__ == "__main__": | |
| 145 main() |
