Sorry, I was wrong. PacketAcknowledgements.requestAck() is necessary when HW acks are used (to set the acknowledgment request field in the packet).
Also, if acknowledgments are enabled (no matter SW or HW), the second negative CCA-pulse should appear (on the CCA-pin of the sender radio chip) which corresponds to the acknowledgment (the first CCA-pulse corresponds to the packet itself). When HW-acks are used, that second pulse appears 128 microseconds after the first one. When SW-acks are used that second pulse appears 880 microseconds after the first one. This means that SW-ack appears in the channel 752 microseconds later than HW-ack. So, apart from the differences between SW- and HW-acks mentioned in TEP126, there is a difference in terms of time: the receiver responds with software acks little bit later than with hardware acks. Anton. _______________________________________________ Tinyos-help mailing list Tinyos-help@millennium.berkeley.edu https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
