Omron CS1W-SLK11-21 - 06-2004, Manual

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Data Link Precautions Section 4-10
the data link status, first check that the Local Node Data Link Active Flag is
ON.
4-10 Data Link Precautions
Be sure to consider the precautions listed below when activating a data link or
adding a node to an existing data link.
Setup and Activation Be sure to consider the precautions listed below when setting up and activat-
ing a data link.
1,2,3... 1. Refresh parameters must be set for each node in the data link when man-
ually generating data link tables. When a data link is started in a node that
does not have a data link table, a data link table error will occur and the
LNK indicator on that node will flash.
Refresh parameters must be set for all nodes that are included in the com-
mon link parameters in the startup node.
2. When data links are automatically generated, the node addresses of all the
nodes in the data link must be in the range resulting from the Communica-
tion Unit Settings.
For example, if the settings divide the data link area among nodes number
1 to 4 (16 CIO words and 32 DM words), node 5 cannot participate in the
data link.
3. With manual generation of data link tables, the node address of the local
node must be included in the local refresh parameters.
4. If the beginning CIO or DM word in the refresh parameters is set too large,
the CIO or DM Area will be exceeded during automatic allocation of link
words.
If the data area is exceeded in the startup node, the LNK indicator on the
startup node will flash and the data link will not operate. If the data area is
exceeded in another node, the LNK indicator on that node will flash and it
will not participate in the data link.
5. If the communications cycle time in data link tables is not generated auto-
matically, and the setting for communications cycle time is too short, the
CS-series SYSMAC LINK Unit (CS1W-SLK11/21) will not participate in the
data links. The LNK indicator on the Unit will flash quickly, and a data link
table communications cycle time settings error (021D Hex) will be regis-
tered in the error log. If this CS-series SYSMAC LINK Unit is the startup
node for the data link, the data link will not be activated. The minimum pos-
sible communications cycle time setting can be obtained using the follow-
ing calculation:
Minimum possible communications cycle time setting =
Maximum node address
×
0.01
+ Number of polled Units
×
0.25
+ Number of Link Units
×
0.161
+ Total number of words in link area
×
0.01
+ 5.322 (ms)
Round up the result of this calculation to obtain a value in milliseconds.