0.17.0 Release Notes

This release contains a number of new features that will break existing code.

New ListOf Classes

Change SequenceOf to ListOf for property definitions and values

The object class definitions started out being generated from the ASN.1 descriptions of objects in Annex C which has since been deleted. That notation used forms like this:

    active-vt-sessions    [5] SEQUENCE OF BACnetVTSession OPTIONAL,

which were translated into BACpypes definitions like this:

    OptionalProperty('activeVtSessions', SequenceOf(VTSession))

But the standard changed to definitions like this (and no longer in an Annex):

    Active_VT_Sessions    BACnetLIST of BACnetVTSession

So BACpypes now uses definitions like this:

    OptionalProperty('activeVtSessions', ListOf(VTSession))

New RouterInfoCache

No change to BACpypes applications unless NetworkServiceAccessPoint has been subclassed

The network service layer consisting of NetworkAdapter, NetworkServiceAccessPoint, and the NetworkServiceElement had no mechanism for a BACpypes application to provide the address of a router, all of the path information it gathered by inspecting upstream packets. It also did not suspend application layer requests to try and find a path, it simply broadcast the request, which is incorrect.

There is a new RouterInfoCache class that can be subclassed and provided to the network layer and it is similar to the DeviceInfoCache at the application layer. A well-known set of functions are called for finding out routing paths for downstream packets and updating paths for upstream packets.

There is a queue of APDU's waiting path discovery in pending_nets. There is (currently) no signal back to the application when the discovery process times out.

LocalDeviceObject moved

The LocalDeviceObject is used to create a DeviceObject in an application that automatically returns the system date and time when the localDate and localTime properties are read. This class was in the bacpypes.service.device module and it has been moved to the new bacpypes.local.device module.

BACpypes applications must change from this:

from bacpypes.service.device import LocalDeviceObject

to this:

from bacpypes.local.device import LocalDeviceObject

Similarly, the CurrentPropertyList class that was in the bacpypes.service.object module is now in the bacpypes.local.object module because it belongs with local implementations of objects.

Local File Objects Moved

The LocalRecordAccessFileObject and LocalStreamAccessFileObject classes have moved to the bacpypes.local.file module.

New LocalScheduleObject Class

There is an implementation of a LocalScheduleObject in the bacpypes.local.sched module. It includes a companion class, an "interpreter" that is a task that keeps the present value current. It does not support writing to or overriding objects outside of the local device context.

Automatic Protocol Services Supported

All of the sample applications that have a full stack had code that computed the protocol services supported and set that in the device object.

    # get the services supported
    services_supported = this_application.get_services_supported()
    if _debug: _log.debug("    - services_supported: %r", services_supported)

    # let the device object know
    this_device.protocolServicesSupported = services_supported.value

This functionality has been rolled into the LocalDeviceObject so this code must be removed.

Traffic Log

There is a new traffic_log attribute in the VLAN networking that can reference a function to call to log each of the PDUs that the network will process. This was added to make debugging tests easier.

Sample Applications

All of the sample applications have been updated with the changes listed above.

There is a new LocalScheduleObject.py sample application that tests for specific dates and times in a variety of schedule objects. The sample schedules could be used for additional, more detailed, and better coverage tests.

The ReadWriteProperty.py sample application has a funky interpreter for making sure values being written can be coerced into appropriate values.