Murata DNT24 Series, Руководство по интеграции

Страница: 46 / 84

NumSlots - this parameter sets the number of slots available for child transmissions following the parent’s beacon trans-
mission on a hop.
BaseSlotSize - this parameter set the maximum number of payload bytes that the base can send on a single hop. The
default value is 40 bytes.
SlotLease - this parameter set the number of hops a parent radio will reserve a slot for a child after
receiving a message from that child. Small values such as 2 are suited to short data bursts, and larger values are general-
ly a better choice when devices send a stream of non-continuous data across consecutive hops. The minimum value is 1,
assuring that a child can receive an ACK on the next hop after it transmits.
BcstAttemptLimit - setting this parameter to 0 enables automatic broadcast message repeats based on the ArqAttempt-
Limit parameter value. Setting this parameter to a value between 1 and 254 specifies the number of broadcast message
repeats independent of the ArqAttemptLimit . This parameter should not be set to 0 if ArqAttemptLimit is set to 255.
ArqAttemptLimit - this sets the maximum number of attempts that will be made to send a message on the RF link. Setting
this parameter to the maximum value of 255 is a flag value indicating that there should be no limit to the number of at-
tempts to send each packet (infinite number of attempts). This mode is intended for point-to-point networks in serial data
cable replacement applications where absolutely no packets can be lost. Note - if this mode is used in a multipoint net-
work, one remote that has lost link will shut down the entire network if the base is trying to send it data.
LinkDropThreshold - this is the number of consecutive beacons missed by a remote that causes the
remote to restart a link acquisition search. Please contact MURATA technical support before making changes to the pa-
rameter.
P2PReplyTimeout - this parameter sets the reply timeout for peer-to-peer messages sent from one node to another. Be-
cause each leg of the journey from one node to another and back may take multiple transmit attempts, the length of time
to confirm receipt and issue a
TxDataReply is subject to more variation than a transmission directly between a base and a
remote. When AckEnable is selected, the P2PReply-Timeout parameter specifies the maximum number of hops or hop
pairs that a remote will wait for a reply from its recipient. If a reply returns sooner than the timeout, the remote will send a
TxDataReply indicating success (ACK) to its host as soon as it is received, and cancels the timeout. If a reply does not
come back before the timeout expires, the remote will send a TxDataReply to its host indicating failure (NAK). If a reply
should come back after the timeout expires the remote will ignore it, as a TxDataReply has already been sent. The units
of this parameter are in hops for point-to-point and point-to-multipoint operation and in hop pairs for store-and-forward op-
eration.
RegistryTimeout - this parameter sets the number of hops without contact from a child device for which a parent device
will preserve the Transaction ID (TID) history for that child. The TID is used to filter out
duplicate packets. After a registry timeout occurs, the TID history is discarded.
NumBaseParms - this parameter controls the number of cycled parameters sent in the base station beacon. It must be left
in its default value of 21 until all nodes in a DNT24 system have received all cycled parameters and stored them locally in
EEPROM. At this point the number of cycled parameters can be set to 8, which will significantly speed up future system
resynchronizations.
©2009-2014 by Murata Electronics N.A., Inc.
DNT24 Integration Guide R2.0 - 10/27/14
www.murata.com