Lucent Technologies 7400B manual Connector Description, Front Panel LED Indicator Descriptions

DEFINITY Communications System	CHAPTER 1: INTRODUCTION
7400B Data Module
User’s Guide	Page 1-3

Connector	Description
POWER/	This red LED lights as long as power is applied to the data module. This LED
TEST	flashes during any test mode, except the start-up self-test. It also flashes along
	with the DATA LED if the connection with the PBX is lost.
DATA	This red LED lights to indicate the state of the CTS (Clear To Send) output lead
METERING	when the Data Metering option is enabled.
A A	Automatic Answer. This red LED flashes to indicate an incoming call and
	lights continuously when the data module is operating in Automatic Answer
	mode.
CD	Carrier Detect. This red LED lights as long as communication is established
	with the far end device.
RD	Receive Data. This red LED lights when received data is being transferred
	from the 7400B Data Module to the local terminal device.
SD	Send Data. This red LED lights when transmitted data is being transferred from
	the local terminal device to the 7400B Data Module.
TR	Terminal Ready. If the &d0 option is enabled, the red LED is on continuously;
	if either the &d1 or &d2 option is enabled, this LED indicates the state of the
	DTR lead (see description of &d command in Appendix A).
OH	Off Hook. This red LED lights continuously from the time a data
	communications call is initiated until the call is terminated.
CHECK	This red LED lights when a call set up fails because of an incompatibility
SPEED	between the configuration of the local terminal device and the far end device.
	The incompatibility will usually occur if a common operating speed cannot be
	achieved between the two endpoints. Chapter 5, “Troubleshooting,” provides
	information about this and other conditions that may cause this LED to light.
DATA	This green LED lights to indicate that a data call is in progress. This LED
	flashes along with the POWER/TEST LED if the connection with the PBX is
	lost.

TABLE 1-1 Front Panel LED Indicator Descriptions