Embedded Web Server for the CR16
National Semiconductor
Jeff Wright
29
Modeled after the Dynamic Host Configuration Protocol (DHCP) used by PC’s to dynamically acquire
its network configuration, a similar mechanism is employed to allow nodes to acquire certain needed
network configuration data automatically. Using what we refer to as “Dynamic Node Configuration”
(DNC), nodes may be added and deleted in a manner similar to the plug-and-play mechanism used in
your PC. As a node is added, it issues a DNC request to the DNC server (located on the gateway),
advertising it’s randomly generated ID. The gateway’s DNC server layer will then assign a new node
number for this node and add it to its list of active nodes. If space is available, and the ID
requested by the node is valid, DNC will acknowledge the request with a confirmation. Subsequent
communications directed at that node will use the negotiated ID. Figure 26 illustrates this table
after adding the first node. The number of nodes used in the demonstration was four, however,
the only real limitation to the number of nodes that may be added is that of the size of the EE,
where this node configuration table is kept.
Figure 25. An Embedded Motor Control Page from the Project
