Mercurial > ~darius > hgwebdir.cgi > pyinst
annotate scpisock.py @ 75:576f112e0aba
Fix read timeout handling so it works over imperfect links.
| author | Daniel O'Connor <doconnor@gsoft.com.au> |
|---|---|
| date | Fri, 27 Sep 2024 09:27:33 +0930 |
| parents | b6ebe05f250f |
| children |
| rev | line source |
|---|---|
| 22 | 1 #!/usr/bin/env python |
| 2 | |
| 3 # Copyright (c) 2011 | |
| 4 # Daniel O'Connor <darius@dons.net.au>. All rights reserved. | |
| 5 # | |
| 6 # Redistribution and use in source and binary forms, with or without | |
| 7 # modification, are permitted provided that the following conditions | |
| 8 # are met: | |
| 9 # 1. Redistributions of source code must retain the above copyright | |
| 10 # notice, this list of conditions and the following disclaimer. | |
| 11 # 2. Redistributions in binary form must reproduce the above copyright | |
| 12 # notice, this list of conditions and the following disclaimer in the | |
| 13 # documentation and/or other materials provided with the distribution. | |
| 14 # | |
| 15 # THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND | |
| 16 # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
| 17 # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
| 18 # ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE | |
| 19 # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
| 20 # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
| 21 # OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
| 22 # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
| 23 # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
| 24 # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
| 25 # SUCH DAMAGE. | |
| 26 # | |
| 27 | |
| 28 import select | |
| 29 import socket | |
| 30 | |
| 31 # See this for more info | |
| 32 # http://www.staff.uni-bayreuth.de/~btp918/cmt2007/geraete/agilent_34410A_dmm/manual/SCPI_Sockets.pdf | |
| 33 # | |
| 34 # ToDo: Implement the SRQ & DCL channel (I don't have any supported hardware) | |
| 35 | |
| 36 SCPI_PORT = 5025 | |
| 37 | |
| 38 class SCPISockDevice(object): | |
|
74
b6ebe05f250f
Add some commentry about what it works with
Daniel O'Connor <doconnor@gsoft.com.au>
parents:
28
diff
changeset
|
39 def __init__(self, host, port = SCPI_PORT): |
| 22 | 40 self.sock = socket.create_connection((host, port)) |
| 41 | |
| 42 def flush(self): | |
| 43 while True: | |
| 44 r, w, x = select.select([self.sock], [], [], 0) | |
| 45 if len(r) == 0: | |
| 46 break | |
| 47 self.sock.recv(1024) | |
| 48 | |
| 49 def write(self, data): | |
| 50 trail = '' | |
|
74
b6ebe05f250f
Add some commentry about what it works with
Daniel O'Connor <doconnor@gsoft.com.au>
parents:
28
diff
changeset
|
51 if data[-1] != b'\n': |
|
b6ebe05f250f
Add some commentry about what it works with
Daniel O'Connor <doconnor@gsoft.com.au>
parents:
28
diff
changeset
|
52 trail = b'\n' |
|
b6ebe05f250f
Add some commentry about what it works with
Daniel O'Connor <doconnor@gsoft.com.au>
parents:
28
diff
changeset
|
53 |
| 22 | 54 self.sock.send(data + trail) |
| 55 | |
| 56 def read(self, timeout = None): | |
|
74
b6ebe05f250f
Add some commentry about what it works with
Daniel O'Connor <doconnor@gsoft.com.au>
parents:
28
diff
changeset
|
57 res = b'' |
| 22 | 58 if timeout == None: |
| 59 timeout = 0.1 | |
|
74
b6ebe05f250f
Add some commentry about what it works with
Daniel O'Connor <doconnor@gsoft.com.au>
parents:
28
diff
changeset
|
60 |
| 22 | 61 while True: |
| 62 r, w, x = select.select([self.sock], [], [], timeout) | |
| 63 if len(r) == 0: | |
| 64 break | |
| 65 res = res + self.sock.recv(1024) | |
|
74
b6ebe05f250f
Add some commentry about what it works with
Daniel O'Connor <doconnor@gsoft.com.au>
parents:
28
diff
changeset
|
66 if res[-1] == b'\n': |
| 22 | 67 break |
| 68 | |
|
74
b6ebe05f250f
Add some commentry about what it works with
Daniel O'Connor <doconnor@gsoft.com.au>
parents:
28
diff
changeset
|
69 return res.rstrip(b'\n') |
|
b6ebe05f250f
Add some commentry about what it works with
Daniel O'Connor <doconnor@gsoft.com.au>
parents:
28
diff
changeset
|
70 |