Xerox FS 3270 Operation of Xerox FS, Indicators of the Xerox FS, CU Contact with Control Unit

Operation

Xerox FS 3270, User's Guide

3. Operation of Xerox FS 3270

The Xerox FS 3270 top panel has been designed to register the operation of the box via the four following indicator LEDs :

∙CU (contact to Control Unit)

∙PAR (parallel input)

∙SER (serial input)

∙READY (printer)

3.1.The Indicators of the Xerox FS 3270

CU (Contact with Control Unit)

This indicator LED has 3 states:

State	Indication
ON	Contact with the control unit.
BLINKING	1. Contact with the control unit, and data pending
	in the Xerox FS 3270 buffer.
	2. Indicates that the TEST switch has been
	activated and the box is ready to enter on-line
	HEX dump mode
	3. The CU indicator will be blinking rapidly while
	the rotary switch is in the “T” position. This is an
	indication that the “T” position is not a valid
	permanent position.
OFF	No contact to the control unit, or the contact has
	been broken for more than 1 minute.

PAR (Parallel input)

The indicator LED has 2 states:

State	Indication
ON	Indicates that the box is processing data from the
	Centronics parallel port
OFF	Indicates that the box is idle or processing data
	from the coax/RS inputs

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