Murata Electronics North America 2410P Manual Do Utilizador
WIT2410P
© 2000- 2008 Cirronet™ Inc
8
M-2410P-0000 Rev G2
When a remote links to a base and requests registration, it requests by default that it be
assigned handle 30H. This default request can be changed by the Set Default Handle
command. If that handle is not currently in use by another remote, the base will assign
that handle to the remote. If the requested handle is already in use by another remote, the
base will assign the next higher handle that is available. Thus, if a remote requests handle
30H and that handle is already assigned, the base will assign the remote handle 31H if
that is available. If 31H is already assigned, the base will assign handle 32H is that is
available and so on.
When a remote leaves the coverage area of the base or otherwise loses link, e.g. the
remote was turned off or put into sleep mode, the base detects this event when the remote
does not renew its registration within 255 hops. With the default setting of 10msec per
hop, this could be as along as 2.55 seconds. If within this time the remote re-establishes
link with the base, the previous handle assigned to this remote will still be marked active
in the base radio. Thus the remote will be assigned a new handle. If the base radio is in
one of the protocol modes, a new CONNECT packet will be issued indicating the current
handle assigned to the remote. The remote is identified by the serial number that is
contained in the CONNECT packet.
If the radio is to be used in a point-to-point mode where there is only one base and one
remote, using the point-to-point mode command of the radios will override this handle
mechanism and always assign the remote the same handle.
2.2.4. TDMA Operation
For applications needing guaranteed bandwidth availability, the TDMA operation of the
WIT2410 can meet this requirement. In the WIT2410 TDMA scheme, each remote has
an assigned time slot during which it can transmit. The base station time slot is set
independently of the remote time slots through the Set Base Slot Size command. The
base station assigns each remote a time slot and informs the remotes of the size of the
time slot. All remote time slots are the same size that is determined by the number of
remotes registered with the base station. The slot size is a dynamic variable that changes
as the number of registered remotes changes. The remotes are continually updated with
the time slot size. This approach continually maximizes the data throughput. The base
station divides the amount of time available per hop by the number of registered remotes
up to a maximum of 16 times slots per hop. If the number of registered remotes is greater
than 16, the time slots will be spread across the required number of hops. For networks
with more than 16 possible remotes, the Set Duty Cycle command must be used to specify
a duty cycle -- the number of hops over which the time slots must be spread. For 1 to 16
remotes, no duty cycle is required; for 17 to 32 remotes a duty cycle of at least ½ is
required; and for 33 to 62 remotes a duty cycle of ¼ or more is necessary. An added
benefit of using the power save mode to set a duty cycle is improved average current
consumption efficiency. Refer to the Status Commands section for details of this
command.
assigned handle 30H. This default request can be changed by the Set Default Handle
command. If that handle is not currently in use by another remote, the base will assign
that handle to the remote. If the requested handle is already in use by another remote, the
base will assign the next higher handle that is available. Thus, if a remote requests handle
30H and that handle is already assigned, the base will assign the remote handle 31H if
that is available. If 31H is already assigned, the base will assign handle 32H is that is
available and so on.
When a remote leaves the coverage area of the base or otherwise loses link, e.g. the
remote was turned off or put into sleep mode, the base detects this event when the remote
does not renew its registration within 255 hops. With the default setting of 10msec per
hop, this could be as along as 2.55 seconds. If within this time the remote re-establishes
link with the base, the previous handle assigned to this remote will still be marked active
in the base radio. Thus the remote will be assigned a new handle. If the base radio is in
one of the protocol modes, a new CONNECT packet will be issued indicating the current
handle assigned to the remote. The remote is identified by the serial number that is
contained in the CONNECT packet.
If the radio is to be used in a point-to-point mode where there is only one base and one
remote, using the point-to-point mode command of the radios will override this handle
mechanism and always assign the remote the same handle.
2.2.4. TDMA Operation
For applications needing guaranteed bandwidth availability, the TDMA operation of the
WIT2410 can meet this requirement. In the WIT2410 TDMA scheme, each remote has
an assigned time slot during which it can transmit. The base station time slot is set
independently of the remote time slots through the Set Base Slot Size command. The
base station assigns each remote a time slot and informs the remotes of the size of the
time slot. All remote time slots are the same size that is determined by the number of
remotes registered with the base station. The slot size is a dynamic variable that changes
as the number of registered remotes changes. The remotes are continually updated with
the time slot size. This approach continually maximizes the data throughput. The base
station divides the amount of time available per hop by the number of registered remotes
up to a maximum of 16 times slots per hop. If the number of registered remotes is greater
than 16, the time slots will be spread across the required number of hops. For networks
with more than 16 possible remotes, the Set Duty Cycle command must be used to specify
a duty cycle -- the number of hops over which the time slots must be spread. For 1 to 16
remotes, no duty cycle is required; for 17 to 32 remotes a duty cycle of at least ½ is
required; and for 33 to 62 remotes a duty cycle of ¼ or more is necessary. An added
benefit of using the power save mode to set a duty cycle is improved average current
consumption efficiency. Refer to the Status Commands section for details of this
command.