Omron NT - SUPPORT TOOL FOR WINDOWS V4 Operation Manual page 543

Limits on Numbers of Elements
Limits on display
For elements, limits are also applied to display in addition to the limits on the
numbers shown above.
S Limits on reading the data
For the NT21, NT31, NT31C, NT631, and NT631C, the allowable number of
data entries that can be read at the same time is set and read elements exceed-
ing this limit are not displayed. If the same data is read from different elements,
reading of the data is counted separately.
Refer to the appendix in the NT21/31/631 Reference Manual for the allowable
maximum number of data entries that can be read.
Appendix F
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