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SNAPlink User Guide — 116-081614-031-A000
Client 1 and Client 2 to
On
for the Multi-cast Forwarded Groups should help make sure all transmissions are received
by Client3. (Note that return messages from Client3 to the Master will also require that Client1 and Client2 have Mesh
Override disabled.)
In a point-to-multipoint environment where the master device can directly communicate reliably with all of the slaves,
the default value of 0 is appropriate. Setting the value higher will cause devices that do not have the
Multi-Cast
Forwarded Groups
feature disabled to unnecessarily forward the data packet, increasing radio chatter. In point-to-
point environments, this setting does not affect communications.
In a directly paired environment, this setting has no effect.
UART Tab
The UART tab contains three parameters for fine tuning data transmission. These can be set according to the needs
of the serial device. You may have to adjust them depending upon transmission speed and the size of data packets.
Buffering Timeout
This setting controls the overall serial data timeout. The value is in
milliseconds with the default being 0, indicating no timeout enforcement.
The
Buffering Timeout
controls the elapsed time between an initial
character being received and a packet of serial data being enqueued for
processing. When the timeout passes, regardless of the number of
characters buffered (other than zero) or the rate at which they are
received, the buffered data will be sent. The larger this value, the more
buffering that will take place. While this allows for more data to be sent per
packet, which might be more efficient depending upon your application, it
also increases latency.
Note that other events, controlled by
Buffering Threshold
and
Inter-
character Timeout
, can also trigger the buffer of data to be sent.
Buffering Threshold
This setting indicates the level where the SNAPlink device will decide that it has enough data to send a packet. If
data comes in faster than the threshold checks it is possible the packet size may be larger than the size specified.
The default is 100 bytes, and the maximum is 123 bytes. Values over 100 are not recommended as they could result
in buffer overrun.
Buffering Threshold
causes buffered data to be sent whenever the threshold is reached. However, triggering the
Buffering Timeout
or
Inter-character Timeout
settings could cause data to be sent before the threshold is reached.
Each packet of data includes a header, which comprises 12 bytes for multipoint packets and 15 bytes for point-to-
point packets. So, the actual number of data bytes sent will be either 12 or 15 bytes fewer.
