Mitsubishi Electric MELSEC-I/OLINK Handbook page 4

When the QJ51AW12D2 is used
[Design Precautions]
● An AnyWire DB A20 system has no control function for ensuring safety.
● When connecting a peripheral with the CPU module or a personal computer with an intelligent
function module to modify data of a running programmable controller, configure an interlock circuit in
the sequence program to ensure that the entire system will always operate safely. For other forms of
control (such as program modification or operating status change) of a running programmable
controller, read the relevant manuals carefully and ensure that the operation is safe before
proceeding. Especially, when a remote programmable controller is controlled by an external device,
immediate action cannot be taken if a problem occurs in the programmable controller due to a
communication failure. To prevent this, configure an interlock circuit in the sequence program, and
determine corrective actions to be taken between the external device and CPU module in case of a
communication failure.
● Do not write any data to the "system area" of the buffer memory in the intelligent function module.
Also, do not use any "use prohibited" signals as an output signal from the CPU module to each
module. Doing so may cause malfunction of the programmable controller system.
[Design Precautions]
● Although an AnyWire DB A20 system features high noise immunity, keep a distance of 100mm or
more between the transmission cables or I/O cables and the high-voltage cables or power cables.
Failure to do so may cause malfunction.
● Configure safety circuits, such as an emergency stop circuit and interlock circuit, external to the
AnyWire DB A20 system.
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WARNING
CAUTION