Sharp Z-336J - Manual (Page 178)

15-24
Chapter 15: Appendix
15
Participation in an existing network
When the JW-50FL receives a token within the participating token detection time, it concludes that it
is linked to a network that is already established, and waits for a participation request frame up to
three token cycles. During this interval, it checks for duplicate use of its node number and address,
as well as updates the participation node operation table. At this time, if a node has identified a
duplicate use of its address by examining the participation 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. If there are no
problems with the node numbers, a node will send a participation request frame after the waiting time
for sending a participating request frame has elapsed. The participating request frame will be sent,
regardless whether it has a token or not. A node that has identified duplicate use of its node number
will not send a participating request frame and will not send or receive data.
Remarks:
Participation token detection time: the time allowed to check whether the network is in operation
or not.
Cycling: This refers to the point when the smallest node number receives a token that has been
passed around the network.
Waiting time for sending a participation request frame: In order not to create a duplicate node
number with some other node trying to enter, the participation request frame is sent after the node
number x 4ms has elapsed.
Time charge setting when starting: 2
Halted token detection
1st cycle 2nd cycle 3rd cycle
Participating token detection time
Start monitoring
nodes
(After turning ON
the power or
when a reset is
released)
Waiting time for sending a
participation request frame
(Local node number x 4 ms)
Send a participation
request frame