screenshot_dmm.py

import io
import sys
import time
import socket
import struct

from PIL import Image

if len(sys.argv) != 2:
    print("Usage: screenshot_dmm.py <filename>")
    sys.exit(1)

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

s.connect(("dmm.bench", 5025))
# Set data to PNG
s.send(b"HCOP:SDUM:DATA:FORM PNG\r\n")
# Now request a screenshot
s.send(b"HCOP:SDUM:DATA?\r\n")
# Read the first 2 bytes, the definite-length header
# Expected format is `#NMMMMXXXXXXXXXXXXX` where
# `#` indicates definite-length, N is the number of digits for M,
# and MMMM is the number of data bytes, XXXXX are the data bytes.
header = s.recv(2)
assert header[0] == ord("#"), "Expected SCPI definite-length block header"
file_len_len = int(chr(header[1]))
file_len = int(s.recv(file_len_len))
print("File size is", file_len, "bytes")
# We'll store the read data in this bytearray
data = bytearray(file_len)
total_received = 0
# Loop reading data from the socket
while total_received < file_len:
    packet = s.recv(file_len)
    data[total_received:len(packet)] = packet
    total_received += len(packet)
    print("Received", total_received, "bytes")
    time.sleep(0.2)

# Use Pillow to write the file out in whatever format the user wants
img = Image.open(io.BytesIO(data))
img.save(sys.argv[1])

screenshot_psu.py

import io
import sys
import requests
from PIL import Image

if len(sys.argv) != 2:
    print("Usage: screenshot_psu.py <filename>")
    sys.exit(1)

# first log in
requests.get("http://psu.bench/cgi/login?pass=keysight")
# now download screenshot
r = requests.get("http://psu.bench/get/screenshot.bmp")
# convert to PNG and save
img = Image.open(io.BytesIO(r.content))
img.save(sys.argv[1])

screenshot_siglent.py

import io
import sys
import time
import socket
import struct

from PIL import Image

if len(sys.argv) != 3:
    print("Usage: screenshot.py <IP address> <filename>")
    sys.exit(1)

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

# Normally we'd connect on 5025 for automated use, avoiding the user shell
# prompts. However the Siglent SDG2042X does not listen on 5025 with current
# firmware, only 5024, the interactive shell, so use that instead.
s.connect((sys.argv[1], 5024))
# We need to eat up all the junk shell prompts etc
s.recv(1000)
# Now request a screenshot
s.send(b"SCDP\r\n")
# Read the first 6 bytes, the BMP header
header = s.recv(6)
# Check it's a BMP header
assert header[0:2] == b"BM", "Expected BMP header"
# Read the specified file length, which is the number of bytes we have to read
file_len = struct.unpack("<I", header[2:])[0]
print("File size is", file_len, "bytes")
# We'll store the read data in this bytearray
data = bytearray(file_len)
data[0:6] = header
total_received = 6
# Loop reading data from the socket
while total_received < file_len:
    packet = s.recv(file_len)
    data[total_received:len(packet)] = packet
    total_received += len(packet)
    print("Received", total_received, "bytes")
    time.sleep(0.2)

# Use Pillow to write the file out in whatever format the user wants
img = Image.open(io.BytesIO(data))
img.save(sys.argv[2])