Hi!
On Thu, 25 Sep 2008, Renee Azhen wrote:
thanks, Razvan Musaloiu-E,
then what is the usage of CC2420_NO_ACKNOWLEDGEMENTS?
The CC2420_NO_ACKNOWLEDGEMENTS will disable the sending of ACKs. The other
directive related to ACKs is CC2420_HW_ACKNOWLEDGEMENTS which will disable
the software ACKs and enable the hardware ones.
If a sender transmit a packet, then the receiver will reply with a ACK.
If a sender does not request for ACKs then the received will not ACK the
packet. If the packet requests for an ACK and the receiver has disabled
the ACKS then again the ACK will not be sent.
So what interface the sender will use to receive the ACK?
and how does the sender process the ACK message?
Do you know some sample code about this flag? could you please share it with me?
Actually there is such a problem already in the tree in this place:
apps/tests/cc2420/TestAcks
All the best!
Razvan ME
"Razvan Musaloiu-E." <[EMAIL PROTECTED]> 写道： Hi!
On Wed, 24 Sep 2008, Renee Azhen wrote:
Does this flag(CC2420_NO_ACKNOWLEDGEMENTS) is used by mac/link layer?
if the CC2420_NO_ACKNOWLEDGEMENTS was set, then no ack will be sent by
receiver, so the receive.Done event will always return true?
You are talking about AMSend.sendDone? AMSend.sendDone will not return a
fail even if the packet is not acked. To check for that you have to use
the wasAcked from the PacketAcknowledgements interface
(PacketAcknowledgements.nc from tos/interfaces). You also need to use the
requestAck from it before doing a AMSend.send of the packet.
--
Razvan ME
Tony O'Donovan
When a sender tranmits a message to a receiver the receiver can send an
acknowledgment (ACK) message. The purpose of the ACK is to let the
sender know the message was successfully received. If the
CC2420_NO_ACKNOWLEDGEMENTS option is set the receiver does not send an
ACK when it receives a message.
--- Renee Azhen wrote:
hi, all,
I am using the collection protocol, and found that
if I use:
CFLAGS += -DCC2420_NO_ACKNOWLEDGEMENTS
CFLAGS += -DCC2420_NO_ADDRESS_RECOGNITION
in the app makfile, network almost failed, it can't
deliver any packet.
So is there anyone know what is the usage of that
line in Makefile??
thanks
Sam
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