you can now take data using sequence mode! also, updated the README file to include more examples. sock.py now replaces scope.py. sock.py is almost identical, but i renamed the class to Socket and fixed it so that data headers are properly received; previously, it was assumed that the 8 byte header was sent in a single recv() call, which is not always the case. draw.py is a new script to draw waveforms using matplotlib instead of root.

1 files changed, 103 insertions, 0 deletions

diff --git a/sock.py b/sock.py
new file mode 100755
index 0000000..8c6da47
--- /dev/null
+++ b/sock.py
@@ -0,0 +1,103 @@
+#!/usr/bin/env python
+
+import struct
+import socket
+import os
+
+headerformat = '>BBBBL'
+
+errors = { 1  : 'unrecognized command/query header',
+           2  : 'illegal header path',
+           3  : 'illegal number',
+           4  : 'illegal number suffix',
+           5  : 'unrecognized keyword',
+           6  : 'string error',
+           7  : 'GET embedded in another message',
+           10 : 'arbitrary data block expected',
+           11 : 'non-digit character in byte count field of arbitrary data '
+                'block',
+           12 : 'EOI detected during definite length data block transfer',
+           13 : 'extra bytes detected during definite length data block '
+                'transfer' }
+
+class Socket(object):
+    def __init__(self, host, port=1861, timeout=5.0):
+        self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+        self.sock.connect((host, port))
+        self.sock.settimeout(timeout)
+
+    def clear(self, timeout=0.5):
+        """
+        Clear any bytes in the oscilloscope's output queue by receiving
+        packets until the connection blocks for more than `timeout` seconds.
+        """
+        t = self.sock.gettimeout()
+        self.sock.settimeout(timeout)
+        try:
+            while True:
+                self.sock.recv(4096)
+        except socket.timeout:
+            pass
+        self.sock.settimeout(t)
+
+    def send(self, msg):
+        """Format and send the string `msg`."""
+        if not msg.endswith('\n'):
+            msg += '\n'
+        header = struct.pack(headerformat, 129, 1, 1, 0, len(msg))
+        self.sock.sendall(header + msg)
+
+    def check_last_command(self):
+        """
+        Check that the last command sent was received okay; if not, raise
+        an exception with details about the error.
+        """
+        self.send('cmr?')
+        err = int(self.recv().split(' ')[-1].rstrip('\n'))
+
+        if err in errors:
+            self.sock.close()
+            raise Exception(errors[err])
+
+    def recv(self):
+        """Return a message from the scope."""
+
+        reply = ''
+        while True:
+            header = ''
+
+            while len(header) < 8:
+                header += self.sock.recv(8 - len(header))
+
+            operation, headerver, seqnum, spare, totalbytes = \
+                struct.unpack(headerformat, header)
+
+            buffer = ''
+
+            while len(buffer) < totalbytes:
+                buffer += self.sock.recv(totalbytes - len(buffer))
+
+            reply += buffer
+
+            if operation % 2:
+                break
+
+        return reply
+
+    def __del__(self):
+        self.sock.close()
+
+if __name__ == '__main__':
+    import sys
+    import setup
+
+    sock = Socket(setup.scope_ip)
+    sock.clear()
+
+    for msg in sys.argv[1:]:
+        sock.send(msg)
+
+        if '?' in msg:
+            print repr(sock.recv())
+
+        sock.check_last_command()