Add support for custom addressing by supplying a TsapPair to the PLC.
CPU, Rack and Slot properties are still present to preserve backwards
compatibility and to support alternate functionality based on the PLC
type.
- Add netcoreapp3.1 target framework, allowing this to run on linux and macos as well.
- Switch windows snap7 DLL to 64bit version 1.4.2. This also improves UnitTest stability (reduces false positives) on the CI (including appveyor)
- Changing the port used for S7NetTests when communicating with Snap7 to a value > 1000 allows tests to run on Linux without elevated privileges.
This is very fragile with time-dependent cancellation, but I don't know of a better way without messing with the code to be tested.
Seems to only work when the test is run as a single run, not when running the whole test suit.
- Do not allow null string to be passed, raise ArgumentNullException.
- Do not allow string whose ASCII representation is longer than the reserved length, since this currently leads to silent data loss.
- Always write the full binary data length of 2 + reservedLength, since that is what the binary representation of that string is in S7 memory, even if some tail bytes are unused by the current string.
I also suspect that S7WriteMultiple would have chocked on that last bit, but I am not sure. There aren't any tests for writing multiple Dataitems right now.
Adjust tests accordingly. Mostly add some tail bytes where necessary, and assert on exceptions where this is now required.
- Adds true support for 64bit double / LReal datatype.
- Set old Types.Single and Types.Double to obselete. Both class names use .NET types instead of S7 type names, contrary to all other types.
- Remove already obsoleted conversion from DWord to Real. Why is this even necessary?
For users caring about converting from DWord, they can still convert to single. But unless we get LWord support, there won't be a direct conversion to double/LReal.
- Adjust unit tests by removing rounding, testing directly double read/writes.
There is quite a bit of breaking changes at least in the automated Struct and object functions which automatically translate .NET types to appropriate S7 types.
My consideration was that if we ever want to support 64bit types, there is no way against breaking those existing incorrect conversions from 64bit .NET double to 32 bit S7 Real variables.
These unittests fail intentionally as the issue discussion has not reached
a consesual solution. Any solution should pass the unittests added in this commit.
For me the tests work fine even when adjust the "chunk size" in WriteBytesAsync. So Snap7 seems to be fine, at least the current version.
This should probably be tested with some live PLC's as well.
This requires reference types that can be null to be annotated by a ? operator, similar to value types.
This gives the advantage that the compiler can warn against any null dereference exceptions, of which this commits elimits a few.
To make the underlying protocol implementation not any more complicated and to eliminate existing problems, and not that precise error reporting, I replaced some return null statements with explicit Exceptions. This lead to the assumption that those core protocoll functions always return non-null objects if they do not throw, making the PLC code simpler.
Adjust some NotConnected tests to look for explicit PlcException instead of NullReferenceException.
Add new class Types.Dtl by taking the DateTime type and adjusting things.
Also add unit test with binary data calculated by hand. (Need to verify with actual S7 data)
