ADTRAN TRDDS-R warranty Latching Loopback Sequences Number Function Byte Code, Bytes

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Table 5. Latching Loopback Sequences

 

 

Number of

Function

Byte Code

Received

 

 

Bytes

 

 

 

Clear existing

Transition in

Minimum of

loopbacks

progress (TIP)

35 TIP bytes

 

*0111010

 

Identify device

Loopback select

Minimum of

to be looped

code (LSC)

35 LSC bytes

 

*1010101 - OCU

 

 

*0110001 - CSU

 

 

*1000001 - NIE

 

Prepare to loop;

Loopback enabled

Minimum of

send MAP code

(LBE)

100 LBE

after 30 bytes

*1010110

bytes

Activate

Far-End voice

Minimum of

loopback

(FEV)

32 FEV

 

*1011010

bytes

 

 

 

Minimum of 35 TIP bytes required to disable established latching loopback.

*Don't Care bit

Initiating OCU Latching Loopback to Loop the TRDDS-R (US West Only)

¥SW1-6 on the TRDDS-DP must be ON to enable latching loopback response.

¥From a test system or set, send an OCU latching loopback sequence.

¥Send a selected test pattern and test for error-free operation.

¥Upon completion of this test, advance to Terminating OCU, CSU or NIE Latching Loopback for latching loopback termination.

Initiating CSU Latching Loopback to Loop a DSU/CSU (US West Only)

¥SW1-6 on the TRDDS-DP must be ON to enable latching loopback response.

¥From a test system or set, send a CSU latching loopback sequence. This instructs the TRDDS- DP to notify the TRDDS-R of a CSU loopback request. The TRDDS-R will reverse sealing current to the DSU/CSU. The DSU/CSU should loop when reversed sealing current is detected.

¥Send a selected test pattern and test for error-free operation.

¥Upon completion of this test, advance to Terminating OCU, CSU or NIE Latching Loopback for latching loopback termination.

Table 6. Alternating Loopback Sequences

Function

Received Bytes

 

 

Active loopback

Four consecutive bytes of

 

specified loopback code

 

*0101010

- OCU

 

*0101000

- CSU

 

*0101100

- DSU

Maintain loopback and

Data byte alternating with

test for bit errors

loopback code

 

example:

 

 

*DDDDDD1/*0101010

Clear loopback

Four consecutive data

 

bytes without a specified

 

loopback code

 

 

 

*Don't care bit

 

 

 

 

 

Network Interface Equipment Latching Loopback

The NIE latching loopback method can be used to loop the TRDDS-R at all rates. This loopback test may require programming of the loopback select code or the complete sequence into the test system.

Terminating OCU, CSU or NIE Latching Loopback

¥From a test system or set, send a Latching Loopback Disable command (35 TIP bytes).

Total Reach Dataport Bidirectional Loopback Support

The Total Reach dataport will execute a bidirectional loopback when performing a loopback at the dataport. The Total Reach dataport responds to either the OCU or DS0 loopback command, whichever loopback is applicable to the dataport version. Refer to Table 7 for Total Reach dataport loopback support.

61291021L5-5A

Section 61291021L5-5A, Issue 1

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Contents General L5-5A Issue 1, April Clei Code # D4OIKTU8Wiring InstallationOptions 0dB 10dBSignal Meter Display IndicatorsElectrical Code Compliance PinTotal Reach DDS TRDDS-R Loopback Dataports Faceplate IndicatorsBytes Latching Loopback Sequences Number Function Byte CodeAlternating Loopback Sequences Function Received Bytes Network Interface Equipment Latching LoopbackDeployment Guidelines Total Reach Dataport Loopbacks Total Reach DDS DataportsDS0 Warranty and Customer Service