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Chapter 15: Appendix
15
[2] Joining and leaving an FL-net network
(1) Participation in the FL-net
Each node monitors the circuit while the FL-net starts up, to determine the interval of a participating
token detection time. When that time has elapsed, if it does not receive a token, the node concludes
that the network is just starting and tries to join the network as it starts. If it receives a token, it
concludes that it is monitoring a network that is in-ring startup state, and it tries to join the network.
New entry
If the JW-50FL does not receive a token after the participating token detection time has elapsed,
it will prepare to send a trigger, which it sends after 4 ms x its node number. If it receives a trigger
before sending a trigger, it will not send a trigger. After receiving a trigger it will wait 1200 ms to
receive a participation request frame. During that period, it will wait for all of the nodes to send
participation request frames while checking for duplicate use of its node number and address. It
also updates participation node management table. After the time it must wait before sending a
participation request frame (node number x 4 ms) has elapsed, it will send a participation request
frame. At this time, if a node has identified a duplicate use of its address by examining the partici-
pation request frames from other nodes, it sets the common memory top address and common
memory size of area 1 and 2 to zero, and does not send any cyclic data. A node that identifies
duplicate use of its address will set a duplicate address flag and reset the common memory data
to enable, so that the flag will be seen. After the time it must wait before sending a participation
request frame has elapsed, and after referring to the participating node table, the node with the
smallest node number will issue the first token. A node that has identified duplicate use of its node
number will not send or receive data.
Time chart when starting: 1
Start monitoring node
(After power is applied or a reset
is released)
Trigger Participation
request frame
Token
Participation token detection time (3 sec.)
Waiting time before sending a participation
request frame (node number x 4 ms)
Waiting time before receiving a participation
request frame (1.2 sec.)
Node1
Node254
Node2
Node3