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Image capture for Tektronix TDS 1012 Oscilloscope

This is a simple Python script to capture screen shots from a Tektronix scope, rotate them to landscape mode and convert them to PNG. The script simply sits in the background monitoring the serial port and creating the images in a specified directory.

The following settings are required on the TDS 1012:

  1. Printing in PCX format to the RS232 port.
  2. RS232 set to 19200N81.

A null modem cable is required to connect the scope to a PC, I used a USB to DB9 serial adaptor on the PC end.

#!/usr/bin/env python
# 02-May-2014 ShaneG
# Capture data from a Tektronix TDS1012 scope and save as an image.
from sys import argv, stdout
from os import makedirs, remove
from os.path import abspath, exists, isdir, join
from time import sleep, strftime
from PIL import Image
import serial
# What speed to use
BAUD_RATE = 19200
def grabImage(scope, path):
""" Grab a single image from the scope and save it to a file
# Create the file
filename = join(path, strftime("scope_%y%m%d_%H%M%S"))
output = open(filename + ".pcx", "wb")
print "Receiving screen dump to '%s'" % filename
# Now read the data
bytes = 0
last = 0
while True:
data =
if len(data) == 0:
bytes = bytes + len(data)
if int(bytes / 10240) > last:
stdout.write("%dK " % int(bytes / 1024))
last = int(bytes / 10240)
print "Saved %d bytes." % bytes
# Now rotate and convert to a PNG
im = + ".pcx")
im = im.transpose(Image.ROTATE_270) + ".png")
# And delete the PCX file
remove(filename + ".pcx")
# Main program
if __name__ == "__main__":
# Set default
port = "/dev/ttyUSB0"
path = None
# Get command line arguments
index = 1
while index < len(argv):
if argv[index] == "--port":
# Set serial port
index = index + 1
port = argv[index]
elif argv[index] == "--path":
# Set image directory
index = index + 1
path = argv[index]
print "ERROR: Unrecognised argument."
# Next arg
index = index + 1
# Make sure the path exists and is a directory
if path is None:
path = "."
path = abspath(path)
if not exists(path):
if not isdir(path):
print "ERROR: Specified location is not a directory."
print " " + path
# Set up the serial port
scope = serial.Serial(port, BAUD_RATE, timeout = 2)
# And wait for some data
while True:
while scope.inWaiting() == 0:
grabImage(scope, path)

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fhpriamo commented Aug 17, 2015

Works pretty well. Thanks!

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