so i'm trying to learn both python and BACnet using the BACpypes library, and i'm a little bit stuck right now.
I'm trying to make the "WhoIs-IAm" sample application to do an automatic "IAm" broadcast when launched but regarding my newbie skill i'm having trouble to build it.
So there's the sample.
#!/usr/bin/python
"""
This application presents a 'console' prompt to the user asking for Who-Is and I-Am
commands which create the related APDUs, then lines up the coorresponding I-Am
for incoming traffic and prints out the contents.
"""
import sys
from bacpypes.debugging import bacpypes_debugging, ModuleLogger
from bacpypes.consolelogging import ConfigArgumentParser
from bacpypes.consolecmd import ConsoleCmd
from bacpypes.core import run
from bacpypes.pdu import Address, GlobalBroadcast
from bacpypes.app import LocalDeviceObject, BIPSimpleApplication
from bacpypes.apdu import WhoIsRequest, IAmRequest
from bacpypes.basetypes import ServicesSupported
from bacpypes.errors import DecodingError
# some debugging
_debug = 0
_log = ModuleLogger(globals())
# globals
this_device = None
this_application = None
this_console = None
#
# WhoIsIAmApplication
#
class WhoIsIAmApplication(BIPSimpleApplication):
def __init__(self, *args):
if _debug: WhoIsIAmApplication._debug("__init__ %r", args)
BIPSimpleApplication.__init__(self, *args)
# keep track of requests to line up responses
self._request = None
def request(self, apdu):
if _debug: WhoIsIAmApplication._debug("request %r", apdu)
# save a copy of the request
self._request = apdu
# forward it along
BIPSimpleApplication.request(self, apdu)
def confirmation(self, apdu):
if _debug: WhoIsIAmApplication._debug("confirmation %r", apdu)
# forward it along
BIPSimpleApplication.confirmation(self, apdu)
def indication(self, apdu):
if _debug: WhoIsIAmApplication._debug("indication %r", apdu)
if (isinstance(self._request, WhoIsRequest)) and (isinstance(apdu, IAmRequest)):
device_type, device_instance = apdu.iAmDeviceIdentifier
if device_type != 'device':
raise DecodingError, "invalid object type"
if (self._request.deviceInstanceRangeLowLimit is not None) and \
(device_instance < self._request.deviceInstanceRangeLowLimit):
pass
elif (self._request.deviceInstanceRangeHighLimit is not None) and \
(device_instance > self._request.deviceInstanceRangeHighLimit):
pass
else:
# print out the contents
sys.stdout.write('pduSource = ' + repr(apdu.pduSource) + '\n')
sys.stdout.write('iAmDeviceIdentifier = ' + str(apdu.iAmDeviceIdentifier) + '\n')
sys.stdout.write('maxAPDULengthAccepted = ' + str(apdu.maxAPDULengthAccepted) + '\n')
sys.stdout.write('segmentationSupported = ' + str(apdu.segmentationSupported) + '\n')
sys.stdout.write('vendorID = ' + str(apdu.vendorID) + '\n')
sys.stdout.flush()
# forward it along
BIPSimpleApplication.indication(self, apdu)
bacpypes_debugging(WhoIsIAmApplication)
#
# WhoIsIAmConsoleCmd
#
class WhoIsIAmConsoleCmd(ConsoleCmd):
def do_whois(self, args):
"""whois [ <addr>] [ <lolimit> <hilimit> ]"""
args = args.split()
if _debug: WhoIsIAmConsoleCmd._debug("do_whois %r", args)
try:
# build a request
request = WhoIsRequest()
if (len(args) == 1) or (len(args) == 3):
request.pduDestination = Address(args[0])
del args[0]
else:
request.pduDestination = GlobalBroadcast()
if len(args) == 2:
request.deviceInstanceRangeLowLimit = int(args[0])
request.deviceInstanceRangeHighLimit = int(args[1])
if _debug: WhoIsIAmConsoleCmd._debug(" - request: %r", request)
# give it to the application
this_application.request(request)
except Exception, e:
WhoIsIAmConsoleCmd._exception("exception: %r", e)
def do_iam(self, args):
"""iam"""
args = args.split()
if _debug: WhoIsIAmConsoleCmd._debug("do_iam %r", args)
try:
# build a request
request = IAmRequest()
request.pduDestination = GlobalBroadcast()
# set the parameters from the device object
request.iAmDeviceIdentifier = this_device.objectIdentifier
request.maxAPDULengthAccepted = this_device.maxApduLengthAccepted
request.segmentationSupported = this_device.segmentationSupported
request.vendorID = this_device.vendorIdentifier
if _debug: WhoIsIAmConsoleCmd._debug(" - request: %r", request)
# give it to the application
this_application.request(request)
except Exception, e:
WhoIsIAmConsoleCmd._exception("exception: %r", e)
def do_rtn(self, args):
"""rtn <addr> <net> ... """
args = args.split()
if _debug: WhoIsIAmConsoleCmd._debug("do_rtn %r", args)
# safe to assume only one adapter
adapter = this_application.nsap.adapters[0]
if _debug: WhoIsIAmConsoleCmd._debug(" - adapter: %r", adapter)
# provide the address and a list of network numbers
router_address = Address(args[0])
network_list = [int(arg) for arg in args[1:]]
# pass along to the service access point
this_application.nsap.add_router_references(adapter, router_address, network_list)
bacpypes_debugging(WhoIsIAmConsoleCmd)
#
# __main__
#
try:
# parse the command line arguments
args = ConfigArgumentParser(description=__doc__).parse_args()
if _debug: _log.debug("initialization")
if _debug: _log.debug(" - args: %r", args)
# make a device object
this_device = LocalDeviceObject(
objectName=args.ini.objectname,
objectIdentifier=int(args.ini.objectidentifier),
maxApduLengthAccepted=int(args.ini.maxapdulengthaccepted),
segmentationSupported=args.ini.segmentationsupported,
vendorIdentifier=int(args.ini.vendoridentifier),
)
# build a bit string that knows about the bit names
pss = ServicesSupported()
pss['whoIs'] = 1
pss['iAm'] = 1
pss['readProperty'] = 1
pss['writeProperty'] = 1
# set the property value to be just the bits
this_device.protocolServicesSupported = pss.value
# make a simple application
this_application = WhoIsIAmApplication(this_device, args.ini.address)
# 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
# make a console
this_console = WhoIsIAmConsoleCmd()
_log.debug("running")
run()
except Exception, e:
_log.exception("an error has occurred: %s", e)
finally:
_log.debug("finally")I just don't know how to call the do_iam so it starts automatically when the app launches.
Any help ?
Thanks.
