Hitachi FL.NET User Manual page 228

<Remarks>
Enter token detection time:
Period of time for checking whether the network is operating.
Round:
Rounds are determined with respect to the time at which the token addressed to the
lowest node number is received.
Enter request frame transmission wait time:
A enter request frame transmission takes place after an elapse of [self-node number ×
4 ms] in order to avoid a conflict with any other newly entering node.
Token detection aborted
3→4 4→5
Enter token detection time
Node monitoring started
(upon power ON or reset)
(2) Leaving from FL-net
A node number check is conducted upon each token frame reception. If the token frame is
not received from a certain node three successive times, that node is considered to have left
from the FL-net (including a case where a token holder node does not transmit the token even
after an elapse of the token monitoring time).
When a node is considered to have left from the network as explained above, the information
about that node is deleted from the management tables.
First round
N→1 1→2
Enter request frame transmission wait time
(Self-node number × 4 ms)
N→1
Figure 8-8 Startup Timing Diagram 2
Second round
N→1 1→2 N→1
frame transmission
8-15
8 APPENDIXES
Third round
1→2 N→1
Enter request