MVI56E-FLN ♦ ControlLogix Platform
Reference
FA Control Network Ethernet Communication Module
User Manual
ProSoft Technology, Inc.
Page 127 of 155
A node that recognized address overlapping by the participation request
frame reception from other nodes sets the common memory top address and
common memory size of areas 1 and 2 to 0 and does not transmit cyclic data.
At the same time, the node set the address overlapping and reset the
common memory data validity flag.
The node having the smallest node number transmits a token first according
to the participating node management table after the participation request
frame reception waiting time is up.
A node that recognized conflict of node number does not transmit and receive
data at all. A joining error in the network shall be notified to the upper layer.
A conflict of node number / address overlapping check are made when the
node does not yet join the network. At the initial startup status, a conflict of
node number / address overlapping check are made for both nodes that
transmitted a participation request frame and nodes that did not transmit it. If
overlapping is detected, the corresponding processing is performed.
When a node does not receive even one frame during the participation
request frame reception waiting time, the node executes the start up
sequence from monitoring the token for the joining token detection time. If the
existence of other nodes is not recognized in the period from transmission of
the third participation request frame until the participation request frame
reception waiting time is up, the node sets a frame waiting flag. The node
continues to resend a participation request frame until the network is
established.
In case other nodes have fallen off and only one node remains during token
circulation with the result that the node waits for a trigger frame or a token
frame, the above is also applicable.
