Omron manual Maintenance of the NT631/NT631C, Replaceable Backlight Model

Maintenance of the NT631/NT631C		Section 7-3
Error Details	Displayed Probable Cause	Remedy
NAK received	——	Check the settings for allocated words and bits.
		If noise is a possible factor, distance the cable from
		sources of noise and insert a noise filter in the power
		supply line.
		If using the equipment in a location subject to a lot of
		noise, use a cable with a high degree of protection
		against noise for the transmission route. Also make
		the cable as short as possible.
Undefined Command Error	The host is not supported.	Check the PLC model used for the host.
	Instruction level 3 is not effective.	Check that the instruction level setting for the host is
		level 1, 2, 3.
Data Over Flow Error	Communications command from the	Set flow control method in the host.
	host is too long.	Increase transmission interval.
	(With memory link)
	Command transmission to the host is	Check the communications cable.
	not possible.	Check the control method at the PT and the host.
		Increase the communications on speed when it to
		slow.

7-3 Maintenance of the NT631/NT631C

Carry out maintenance work in order to ensure that the NT631/NT631C is always used in its optimum condition.

Spare PT

Backlight (for NT631C- ST141@-EV2/ST151@-EV2 only)

WARNING

Do not attempt to take the unit apart and do not touch any internal parts while the power is being supplied. Doing either of these may result in electrical shock.

It is advisable to have a spare NT631/NT631C available to minimize system downtime in the event of an NT631/NT631C failure or if the screen display becomes difficult to read due to deterioration of the display unit.

When the backlight in the display is getting dim and the screen cannot be read easily, replace the backlight. The backlight can be replaced at the rear of the NT631C-ST141@-EV2/ST151@-EV2 while it is mounted in an operation panel. The backlight for NT631C-ST152@-EV2 and NT631C-ST153@-V3 cannot be replaced by the user. Contact your OMRON service center when the backlight needs to be replaced.

Replaceable Backlight Model

NT631C-CFL01 (for NT631C-ST151@-EV2)

The backlight for the NT631C-ST152@-EV2/ST153@-EV3 cannot be re- placed by the user. Contact your OMRON service center when the battery needs to be replaced.

NT631C-CFL02 (for NT631C-ST141@-EV2)

Guide to Backlight Replacement

Use the following as a guide to backlight replacement.

NT631C-ST141@-EV2: Approx. 25,000 hours

NT631C-ST151@-EV2: Approx. 30,000 hours

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