Echelon Mini EVK - Manual (Page 38)

Figure 3.4 ISI Information Window
The subnet ID, node ID, and Neuron ID of the network interface used by the
Monitoring & Control Application are displayed in the Local Network
Interface box. The subnet ID, node ID, and Neuron ID of the last device to
send an update over the channel are displayed in the Last Device to Send
Update box.
You can force an ISI collision to see how the ISI protocol recovers from ISI
collisions. To force the local network interface to change its subnet and node
ID, click Force ISI Collision. The ISI protocol enables the ISI library to
detect and resolve network address conflicts, thereby maintaining a self-
installed network consisting of devices with unique addresses without the use
of a central database. During the lifetime of an ISI-compliant self-installed
network, it is possible (though unlikely) that multiple devices may
temporarily use the same subnet/node address. The Force ISI Collision
button demonstrates the effect of this by forcing the Mini computer’s network
interface to use the same subnet/node address as the last device to send it an
update. The remote device (i.e. the last device to send an update) will
recognize the situation, take defensive action, and allocate itself a new
subnet/node address. You can use ISI Information window or Echelon’s
LonScanner ™ Protocol Analyzer to observe the resulting message exchange.
You can also observe the action by monitoring the
32 Mini EVK User’s Guide