Omron NX Series Hardware User Manual page 28

Precautions for Safe Use
The Battery is not mounted when the product is at factory setting. The clock data is retained by the
built-in capacitor. The capacitor is charged while the power is supplied and discharged while the
power is not supplied. If the power OFF time rate is high, the clock data is initialized and malfunc-
tions may occur in the program for which the clock data is used.
• If you use the Battery, connect the Sysmac Studio and set the Battery-related error detection to
Use. The Battery-related error detection is set to Do not use at the factory setting because the
Battery is not built in. If the Battery-related error detection is set to Do not use, an error cannot be
detected when the Battery is exhausted and malfunctions may occur in the program for which the
clock data is used.
Debugging
• Forced refreshing ignores the results of user program execution and refreshes I/O with the specified
values. If forced refreshing is used for inputs for which I/O refreshing is not supported, the inputs will
first take the specified values, but they will then be overwritten by the user program. Be careful that
this operation differs from the force-set/reset functionality of the CJ/CP-series PLCs.
• You cannot upload or download information for forced refreshing with the Sysmac Studio.
After downloading data that contains forced refreshing, change to RUN mode and then use the Sys-
mac Studio to perform the operation for forced refreshing.
Depending on the difference in the forced status, the control system may operate unexpectedly.
• Do not specify the same address for the AT specification for more than one variable.
Doing so would allow the same entity to be accessed with different variable names, which would
make the user program more difficult to understand and possibly cause programming mistakes.
• If the number of array elements of a structure array variable that stores the result set returned from
the stored procedure is too large, the DB_ExecuteProcedure instruction may terminate abnormally
due to a Data Capacity Exceeded error (error code: 041B hex).
If the error occurs, reduce the number of array elements of the structure array variable and cycle the
power to the Controller.
General Communications
• When you use data link communications, check the error information that is given in _ErrSta (Con-
troller Error Status) to make sure that no error has occurred in the source device. Create a user pro-
gram that uses reception data only when there is no error in the source device.
If there is an error in the source device, the data for the data link may contain incorrect values.
• Unexpected operation may result if inappropriate data link tables are set. Even if appropriate data
link tables have been set, confirm that the controlled system will not be adversely affected before
you transfer the data link tables. The data links start automatically after the data link tables are
transferred.
EtherNet/IP Communications
• Make sure to use the communications distance, number of nodes connected, and method of con-
nection for EtherNet/IP within specifications. Do not connect EtherNet/IP communications to Ether-
CAT or other networks. An overload may cause the network to fail or malfunction.
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NX-series NX502 CPU Unit Hardware User's Manual (W629)