Omron NT31 NT31C manual Section

Using a Memory Unit (Versions without the -Vj Suffix)			Section 3-6
	Error	Probable Cause	Remedial Action
	Flash memory error	An error occurred during	Turn the NT31/NT31C power
		initialization of the	OFF, then back ON. If the error
		NT31/NT31C or memory	recurs, the flash memory at the
		unit flash memory, or	write destination may be faulty. In
		during write processing.	this case, replace the unit.
	Verify error	An error occurred during	Turn the NT31/NT31C power
		verification processing at	OFF, then back ON. If the error
		the flash memory of the	recurs, the flash memory at the
		NT31/NT31C or the	write destination may be faulty. In
		memory unit.	this case, replace the unit.

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