ALM-5294 CDU Main RX TTA Alarm

Description

This alarm is triggered when both the software switch and hardware switch of the TTA configured for the CDU main receive path are turned on, and the current for the TTA exceeds the specified range (nominal 50?260 mA). The specified range of the current for the TTA is related to the type of the CDU, CDU switches, and TTA. For details, see conditions for TTA current alarms.

Attribute

Alarm ID Alarm Severity Alarm Type
5294 Minor Fault

Parameters

ID Name Meaning
1 Site No.

Number of the site where the faulty board or module is located

Value range: 0-2047
2 Board Type

Number of the type which the faulty board belongs to.

C7:P-CDU

C9:D-CDU
3 Board No.

Number of the fault board

0:CDU 0

1:CDU 1
4 PassNo

Number of the passage where the faulty board is located.
5 SubLink No.

Alarm sub-category number

255: None
6 Cell Index

Index of the cell where the board or module is located

0-2047: Cell index of the faulty cell in the data configuration

65535: None
7 Site Type

Type of the site where the faulty board is located.

3:BTS30;

5:BTS312;

10:BTS3012A;

11:BTS3006A;

12:BTS3012;

13:BTS3006C;

14:BTS3002E;

15:BTS3012AE;

16:BTS3012 II;
8 RackNo

Number of the rack where the faulty board is located.
9 BoxNo

Number of the subrack where the faulty board is located.
10 SlotNo

Number of the slot where the faulty board is located.
11 Site Name

Site Name
12 Alarm Attribute

Alarm Character

0:Normal

1:Transient Count

Impact on the System

This alarm shows that the TTA configured for the main receive path of the CDU cannot work normally. This will lower the receive flexibility of the main receive path of the BTS compared to the receive flexibility when the TTA works normally. However, the BTS can still work normally in this case. vv

System Actions

None.

Possible Causes

  • The power supply circuit of the TTA configured for the CDU main receive path cannot work normally.
  • The TTA configured for the main receive path of the CDU cannot work normally.
  • The antenna feeder tributary between the CDU output port and the TTA, including the jumpers, feeders and lightning arrester is faulty.
  • The CDU alarm circuit is faulty (false alarm).

Procedure

  1. Check the voltage of the power supply for the TTA at the CDU antenna port

    Remove the communication cable from the CDU when it is normally powered up and there is no CDU communication alarm. Turn off the power amplifier of the TRX corresponding to the faulty CDU to stop power transmission. Remove the jumper from the CDU antenna port. Use a multimeter to measure the DC voltage between the inner and outer conductors of the transmit antenna connector of the CDU. Check whether the measured voltage is in the normal range of 11 to 13 V (inner conductor connected with the positive pole).

    NOTE:

    Turn off the power amplifier of the TRX to stop power transmission before disconnecting the jumper between the CDU antenna port and the TRX input port.

    Y=> Go to Step 2.

    N=> Go to Step 3.

  2. Check jumpers and feeders

    At the one end of a removed jumper, measure the voltage between the inner and the outer conductors with a multimeter to see whether they are short-circuited.

    Y=> Further check the antenna feeder segment by segment.

    N=> Go to Step 3.

  3. Replace the CDU

    Replace the CDU and check whether the alarm is cleared.

    Y=> The alarm handling ends.

    N=> Go to Step 4.

  4. Replace the TTA

    Replace the TTA and check whether the alarm is cleared.

    Y=> The alarm handling ends.

    N=> Please contact Huawei Customer Service Center.

Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.