5-4
Section
Checking Data Link Status
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The following shows an example of an insufficient receive area.
Send
area
Receive
area
Data indicated by
Send
area
Receive
area
Data indicated by
Sufficient
is received in
node 2.
Insufficient (short)
Data indicated by
cannot be received in node 2.
and the remaining data is truncated.
is received
Node 1
Node 2
Node 1
Node 2
Note
1. A communications error will occur in a node that is not participating in the
network.
2. When a communications error occurs or a node is separated from the net-
work, previous status will be retained for other node status.
3. A node which is participating in the network but is not participating in the data
links will show the PC operating status and PC error.
4. On the Controller Link Support Board, a node participating in the network
but not in the data links will show the PC operating status, PC errors, com-
munications errors, and data link participation for all nodes.
5. When there is not enough receive data to filling a receive area (“area re-
maining”) at a computer node, the status of the rest of the receive area will
be indeterminate.
5-4-3 Checking by Manipulating Bit/Word Status
Although the data link function itself may be operating correctly, the data link
areas may have been input incorrectly.
After you have confirmed that the data link function is operating normally, check
to see whether or not the data link is operating as intended, i.e., check to see if
the desired bits/words data is being transferred to the intended words at other
nodes.
Change the contents of a bit or word in a data link send area using a Program-
ming Device or the user program and check whether the change is reflected in
data link areas of other nodes as intended.
The contents of the data link areas set on the local node for the Controller Link
Support Board can be read and written using the memory monitor program of the
FinsGateway. For details refer to the FinsGateway online help.
