Hitachi S10mini User Manual page 250

8 APPENDIXES
8.4.2 Entering in/leaving from FL-net
(1) Entering in FL-net
When a node starts up, it monitors the line until an enter token detection timeout occurs. If it
does not receive the token in this instance, it concludes that the network startup process is in
progress, and then newly participates in the network. If it receives the token, on the other
hand, it concludes that it is in a midway enter state, and then participates in the network on the
spot.
(a) New enter
If a node does not receive the token within the enter token detection timeout period, the node
prepares for trigger transmission and then start a transmission after an elapse of
predetermined time which is determined by multiplying the remainder of node number/8 by
4 ms. If trigger reception occurs before trigger transmission, the node does not transmit a
trigger. For a period of enter request frame reception wait time (1200 ms) after trigger
reception, all nodes wait to transmit an enter request frame while checking for a duplicate
node number or address and updating the entering node management table. When the enter
request frame transmission wait time (node number × 4 ms) elapses after trigger reception,
the nodes transmit an enter request frame. If a node recognizes a duplicate address in
accordance with an enter request frame of another node, the former node sets the common
memory starting address and common memory size for area 1 and 2 to 0 and does not
transmit cyclic data. When a node recognizes a duplicate address, it sets an address
duplication flag and resets a common memory data validity notification flag. When an
enter request frame reception wait timeout occurs, a entering node having the lowest node
number transmits the token first in accordance with the entering node management table.
When a node recognizes a duplicate node number, it starts no transmission/reception.
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