def writeCommandsToDevice(self):
try:
while True:
print "writeCommandsToDevice: Waiting for a command to write."
command, resultDefered = self.commandQueue.get_nowait()
print "writeCommandsToDevice: Got a command to write. %s" % repr(command)
transId = Modbus.getTransactionId(command)
self.sentCommands[str(transId)] = resultDefered
command = [ord(c) for c in command]
self.device.write(command, checksum=False, modbus=True)
except Exception, e:
print type(e), e
print "writeCommandsToDevice: No more commands to write."
def loopingRead(self):
self.deviceClosedEvent.clear() # The device isn't close, so set the flag to False.
while self.running:
# Busy wait just for a bit because we recently received a
# command. It's worth busy waiting to see if another will come.
while True:
sleep(0.002)
now = datetime.now()
if now - self.lastCommandTime > BUSY_WAIT_TIME:
break
if not self.commandQueue.empty():
break
if not self.commandQueue.empty():
self.writeCommandsToDevice()
try:
# print "Start read."
packet = self.device.read(64)
# print "Read returned. Len = %s" % len(packet)
if len(packet) != 0:
protoId = Modbus.getProtocolId(packet)
if protoId == 0:
transId = Modbus.getTransactionId(packet)
print "--------------------------------- Calling callback for transId = %s" % transId
self.sentCommands[str(transId)].callback(packet)
self.sentCommands.pop(str(transId))
self.lastCommandTime = datetime.now()
else:
# print "Got spontaneous data!"
self.sendSpontaneousData(packet)
except Exception, e:
if str(e).endswith("-7"):
# print "Read timed out."
pass
elif self.closingDevice:
# We're closing the device anyway.
pass
else:
print type(e), e
self.deviceLost()