Extract waveform data from Siglent oscilloscope binary files

Waveform data can be saved in many formats, but binary (.bin) gives the smallest files and the fastest USB/LAN transfers — essential when a capture holds millions of points. The trade-off: binary is not human-readable. This note explains the structure of Siglent's binary waveform files and how to convert the raw sample codes back into real voltages and time.

The file structure in a nutshell

• A header holds the acquisition context: which channels are on, V/div and offset per channel, timebase, trigger delay, sample rate and the code-per-division scaling
• The data section follows: one sample code per point per enabled channel (8-bit on most models, 16-bit on high-resolution scopes)
• The header layout is versioned via a bin_head_ver field — the official spec documents every version chapter by chapter, with byte-exact offsets (e.g. ch1_vert_code_per_div at 0x268)

The four conversion formulas

Everything you need to reconstruct the waveform comes down to four documented formulas (values from the header; examples from the spec):

sample_rate  = wave_length / (hori_div_num * time_div_val)
vert_offset  = (ch_vert_offset - 220) * (ch_volt_div_val / pixel_per_div)
time_delay   = (time_offset - 349) * (time_div_val / pixel_per_div)
voltage[i]   = (code[i] - 128) * ch_volt_div_val / 1000 / code_per_div + vert_offset

A practical Python skeleton

import numpy as np

with open('SDS_capture.bin','rb') as f:
    raw = f.read()

# 1) read header fields at the offsets for YOUR bin_head_ver (see the spec)
#    e.g. vdiv, vert_offset, sample_rate, code_per_div, data_start, n_points

# 2) slice the data section and convert codes -> volts
codes  = np.frombuffer(raw, dtype=np.int8, count=n_points, offset=data_start)
volts  = codes.astype(float) * vdiv / code_per_div + vert_offset
t      = np.arange(n_points) / sample_rate + time_delay

# 3) plot or process
import matplotlib.pyplot as plt
plt.plot(t, volts); plt.xlabel('s'); plt.ylabel('V'); plt.show()

1,000,000 samples converted -> 1.00 GSa/s, CH1 50 mV/div
peak-peak: 0.312 V   mean: -0.0021 V

Get the full format specification

The complete 62-page specification — every header field, every bin_head_ver version, all unit and magnitude tables — is available as a PDF: How to Extract Data from the Binary File of SIGLENT Oscilloscope (EN03B).