ADTRAN TROCU DP, DSU/CSU LED Indicators, Deployment Guidelines, TRDDS Insertion Loss Measurements

and manual switch settings by pressing the momentary Alternate Provisioning (AP) switch located on the front panel. If the channel unit is removed from the system, the unit retains previous provisioning information in nonvolatile Random Access Memory (RAM).

The REM indicator remains ON when the channel unit is operating based on Remote Provisioning, and is OFF when operating on manual switches. If the channel unit has never been remotely provisioned, the AP switch has no effect and the REM indicator remains OFF. See Table 3 for LED Indicators.

Table 3. LED Indicators

INDICATOR	DESCRIPTION
SYNC LOSS	ON indicates that there is no sync
	between the TROCU DP and the
	remote TRDDS-R; check for
	continuity, load coils, and other
	abnormal line conditions.
NEAR CRC	ON indicates that there are errors
	on the incoming data stream;
	check for the abnormal line
	conditions closer to the TROCU
	DP.
FAR CRC	ON indicates that there are errors
	occurring towards the remote
	TRDDS-R; check for the
	abnormal line conditions closer to
	the TRDDS-R.
REM	ON indicates that the unit has
	been remotely provisioned;
	FLASHING indicates that the
	remote control link is active.
	Push the AP button to toggle
	between manual and remote
	provisioning.
QM DISC	ON indicates that the Quality
	Monitor Disconnect has occurred.
NO DSU	ON indicates the absence of the
	customer DSU/CSU as
	determined by the TRDDS-R.
LBK	ON indicates the OCU or CSU
	loopback activation.
IDLE	ON indicates the presence of the
	Control Mode Idle toward the
	network.

6. DEPLOYMENT GUIDELINES

The TROCU DP and TRDDS-R use technology designed to eliminate the need for repeaters and concerns over impairments caused by typical noise and bridge tap. Table 2 describes cable loss for the TRDDS Nyquist frequency of 13.3 kHz. Listed below are the loop design guidelines for TRDDS (See Tables 2 and 4 for more information).

•All loops must be nonloaded.

•Actual Measured Loss (AML) should not exceed 50 dB at 13.3 kHz (135 Ω termination),

the Nyquist frequency of TRDDS.

NOTE

The 50 dB AML limit includes 6 dB of signal margin to account for potential near-end cross talk (NEXT) from other digital services that may be provisioned in the same binder group.

•Loop length should not exceed 50 kft.

•Bridged tap length should not exceed 12 kft.

•Background noise level should not exceed 34 dBrn.

•Impulse noise level should not exceed -40 dBm, (+50 dBrn).

NOTE

Measure noise with 50 kbit weighting characteristic approximating a filter with a passband of 40 Hz to 30 kHz. Background noise level or impulse noise level is referenced from 56/64 kbps data rate in TR62310.

Table 4. TRDDS Insertion Loss Measurements

TRDDS

13.3kHz compared to 28 kHz for traditional DDS service

Line	@ 13.3 kHz	@ 28 kHz
Configuration
27 kft 26 AWG	50.12 dB	65.35 dB
36.25 kft 24 AWG	50.00 dB	62.50 dB
50 kft 22 AWG	50.24 dB	59.33 dB

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