Nortel Networks 553-3001-211 manual NTBK50 faceplate LEDs Part 2, Dch

NTBK50 2.0 Mb PRI card Page 765 of 894

Table 244

NTBK50 faceplate LEDs (Part 2 of 2)

LED	State	Definition
	Flashing	NTAK20 is equipped and is attempting to lock (tracking
	(Green)	mode) to a reference. If the LED flashes continuously
		over an extended period of time, check the CC STAT in
		LD 60. If the CC is tracking this can be an acceptable
		state. Check for slips and related clock controller error
		conditions. If none exist, then this state is acceptable,
		and the flashing is identifying jitter on the reference.
	Off	The clock controller is not equipped.
DCH	On (Red)	DCH is disabled.
	On (Green)	DCH is enabled, but not necessarily established.
	Off	DCH is not equipped.

Power requirements

The NTBK50 obtains its power from the backplane, drawing up to 2 A on +5 V, 35 mA on +15 V and 20 mA on –15 V.

Environment

The NTBK50 meets all applicable Nortel Networks operating specifications.

Functional description

NTBK50 provides the following features and components:

•recovery of the 2.048 kbps data by the CEPT receiver, at signal levels which have been attenuated by up to 10 dB

•control of CEPT line density using HDB3 which provides 64 kbps clear channel

•performance monitoring of the receive carrier by means of Bipolar Violations (BPV), Slips, CRC-4 (CRC), and Frame Bit Errors (FBER)

Circuit Card Description and Installation