S7nodave for EPICS
   Device support and driver for EPICS communication with S7 PLCs 
================================================================================

ABOUT
-----

S7nodave is a device support and driver for using S7 PLCs with an EPICS IOC,
which is based on Snap7 (http://snap7.sourceforge.net/).

Using s7nodave, you can read variables from or write data to the PLC using the 
ISO on TCP protocol. You only have to specify the memory address and data-type
for each item you want to read or write.


A WORD OF CAUTION
-----------------

When using this software to connect to a PLC, disconnect ALL external equipment
from the PLC before trying to establish a connection.

This software can overwrite variables in the PLC memory or even parts of the
program running in the PLC. Therefore outputs of the PLC might show 
unpredictable behavior.

There are a lot of different PLC types and depending on the type of the PLC, its
configuration, the type of the host machine used for the EPICS IOC, the host 
machine's configuration and the EPICS IOC's configuration, this software might 
have very different, potentially unwanted results.

It is always the responsibility of the user using this software to ensure, that
its use is safe and complies with local regulation BEFORE connecting any 
equipment to the PLC. Violations of this rules might result in equipment being
damaged or even PERSONS BEING INJURED by misbehaving equipment.


COMPILING
---------

You need to add the configure/RELEASE.local file and set the EPICS_BASE and ASYN
variables to the locations of your EPICS Base and Asyn installation directories.

You might also have to add configure/CONFIG_SITE.local and append the
appropriate compiler options (e.g. "-std=c++11") for enabling C++ 11 support to
the USR_CXXFLAGS variable.

As Snap7 is bundled with s7nodave for EPICS, there is no need to compile Snap7
separately. It will be compiled and placed in the lib directory automatically
when running make.


USING THE DEVICE SUPPORT / DRIVER
---------------------------------

In order to use the device support and driver in an IOC, you have to add the
line

S7NODAVE=/path/to/s7nodave

to the configure/RELEASE file of your IOC application. Assuming your IOC 
application name is "xxx", you also have to add the two lines

xxx_DBD += s7nodave.dbd
xxx_LIBS += s7nodave

to the file xxxApp/src/Makefile.

You can the use DTYP "s7nodave" for most record types. The device addresses
have the form "@myPLC IB0" where "myPLC" is the name of a port created using

s7nodaveConfigureIsoTcpPort("myPLC", "s7plc.local.marsching.com", 0, 0, 0)

in iocBoot/iocxxx/st.cmd and "IB0" is a memory address in the usual S7 notation.

Please see the extended documentation in the docs directory for more detailed
information about how to use s7nodave for EPICS.


CONTACTING THE AUTHOR
---------------------

Please refer to the contact information given on our web page 
(http://www.aquenos.com). Bug reports, comments on this software and reports of
applications of this software are always welcome.

================================================================================

Copyright notice for s7nodave for EPICS:
 
Copyright 2011-2021 aquenos GmbH

S7nodave for EPICS is free software: you can redistribute it and/or modify it 
under the terms of the GNU General Public License as published by the Free 
Software Foundation, either version 3 of the License, or (at your option) any 
later version.

S7nodave for EPICS is distributed in the hope that it will be useful, but 
WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more 
details.

You should have received a copy of the GNU General Public License along with 
s7nodave for EPICS.  If not, see <http://www.gnu.org/licenses/>.
 
================================================================================

This software uses EPICS base. Copyright notice for EPICS base:

Copyright (c) 1991-2007 UChicago Argonne LLC and The Regents of the University 
of California. All rights reserved.

For the license of EPICS base please refer to the LICENSE file in the EPICS base
directory.

================================================================================

This software uses Asyn for EPICS. Copyright notice for Asyn:

Copyright (c) 2002 University of Chicago, The Regents of the
University of California, and Berliner Elektronenspeicherring
Gesellschaft fuer Synchrotronstrahlung m.b.H. (BESSY) All rights
reserved.

Copyright (c) 2004 by Danfysik and Cosylab (Danfysik has funded the work
performed by Cosylab).

For the license of Asyn please refer to the LICENSE file in the Asyn directory.

================================================================================

This software uses and distributes (a minimal version of) Snap7. Copyright
notice for Snap7:

Copyright 2013, 2015 Davide Nardella

Snap7 is free software: you can redistribute it and/or modify it under the terms
of the Lesser GNU General Public License as published by the Free Software
Foundation, either version 3 of the License, or (at your option) any later
version.

It means that you can distribute your commercial software linked with Snap7
without the requirement to distribute the source code of your application and
without the requirement that your application be itself distributed under LGPL.

Snap7 is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE.  See the Lesser GNU General Public License for more details.

You should have received a copy of the GNU General Public License and a copy of
Lesser GNU General Public License along with Snap7. If not, see
http://www.gnu.org/licenses/.

================================================================================

This tests for this software use Google Test. Copyright notice for Google Test:

Copyright 2008, Google Inc.
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:

    * Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
    * Redistributions in binary form must reproduce the above
copyright notice, this list of conditions and the following disclaimer
in the documentation and/or other materials provided with the
distribution.
    * Neither the name of Google Inc. nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.