Specifications

ID 3 – Network ID
The 16-bit Network Identifier of the SNAP Node. The Network ID and the Channel are what
determine which radios can communicate with each other in a wireless network. Radios must be set to
the same channel and Network ID in order to communicate over the air. Nodes communicating over a
serial link pay no attention to the channel and Network ID.
Network IDs can be set to any value from 0x0000 through 0xFFFF. However 0xFFFF is a wildcard
value to which all nodes respond and should generally be avoided. The default Network ID is 0x1C2C.
ID 4 – Channel
The channel on which the SNAP Node broadcasts. See also, Network ID.
The channel can be set to any value from 0 to 15. The Channel Analyzer in Portal can help you
determine which channel has the least traffic on it in your environment. The default channel is 4.
ID 5 – Multi-cast Processed Groups
This is a 16-bit field controlling which multi-cast groups the node will respond to. It is a bit mask, with
each bit representing one of 16 possible multi-cast groups. For example, the 0x0001 bit represents the
default group, or “broadcast group.”
One way to think of groups is as “logical sub-channels” or as “subnets.” By assigning different nodes
to different groups, you can further subdivide your network.
For example, Portal could multi-cast a “sleep” command to group 0x0002, and only nodes with that bit
set in their Multi-cast Processed Groups field would go to sleep. (This means nodes with their group
values set to 0x0002, 0x0003, 0x0006, 0x0007, 0x000A, 0x000B, 0x000E, 0x000F, 0x0012, etc.,
would respond.) Note that a single node can belong to any (or even all) of the 16 groups.
Group membership does not affect how a node responds to a direct RPC call. It only affects multi-cast
requests.
ID 6 – Multi-cast Forwarded Groups
This is a separate 16-bit field controlling which multi-cast groups will be re-transmitted (forwarded)
by the node. It is a bit mask, with each bit representing one of 16 possible multi-cast groups. For
example, the 0x0001 bit represents the default group, or “broadcast group.”
By default, all nodes process and forward group 1 (broadcast) packets.
Please note that the Multi-cast Processed Groups and Multi-cast Forwarded Groups fields are
independent of each other. A node could be configured to forward a group, process a group, or both. It
can process groups it does not forward, or vice versa.
NOTE – If you set your bridge node to not forward multi-cast commands, Portal will not be able to
multi-cast to the rest of your network.
SNAP Reference Manual Document Number 600-0007K Page 93 of 202