Analysis and Handling of Common Faults of HICOM programmable Switches

HICOM 390 devices adopt hierarchical processing and function-sharing methods, which are divided into three levels: central control system, group processing system, and user relay unit. Both the central control system and time-division switching network have two hot backups, the performance of the entire machine is relatively stable. This Section classifies faults occurring during the operation, analyzes the causes of each fault type, and summarizes the troubleshooting methods.

1 software fault

The HICOM system has a software package for Fault Handling. If the software or data fails to a certain extent, the system will soft-start and update some software and data in the faulty part, make the system work normally again.
1) active/standby CPU Switching

The HICOM system contains two sets of cpus. When the master CPU is used, the slave CPU receives the relevant information at the same time to keep consistent with the CPU data. When a software fault is serious to a certain extent, the primary CPU cannot run normally. The standby CPU runs automatically or manually switches to press the RES key on the DPLM board. The original master CPU reloads data from ADS and becomes the backup CPU. Data will not be lost during the switchover, and the call user will not lose the call.

2) User cabinet announcement

All users of a single cabinet call, and users of other cabinets can dial normally. The dial tone is provided by the signal unit board SIU of each peripheral cabinet group processing unit, which is usually defined by software data. There are two reasons for the user to scream: the SIU Board Fault of the Cabinet and the software data fault. Check whether the SIU board is normal. This indicates that the software is faulty. Press the RES key on the DPLM board in the group to reload data from the central cabinet. After loading, the user resumes normal dialing.

2. maintenance terminal faults

The maintenance terminal F500 communicates with the vswitch through the V.24 interface. It is connected to the Management Server ADS and is mainly used for system management and user data input and output. It is the main maintenance tool.

1) communication with the switch is interrupted

In this case, check the port indicator on the LCU of The Link Control Panel. The indicator light is off. In this case, port self-protection is disabled and the link cannot be connected, resulting in a doubling of interruption. Perform the following steps in sequence:

First use the AMO command switch: ACT-LSSM: AI, 8;
② Load the LCU board data by pressing the LT link twice on the key-Road Bus Control Panel LBC.
③ Reload ADS data by pressing the REST key on the DPLM of the data processor board.
④ Turn off the ADS power and restart.

V.24 port self-protection is disabled and may be restored in any of the above four steps. If the fault persists, the V.24 port is damaged and the LCU board needs to be replaced.

2) the keyboard does not work.

Check whether the keyboard is normal and the V.24 interface is normal. Press the keyboard without any response. The F500 terminal has an internal ticket. You can set two passwords: one is the password and the other is the keyboard password. If the maintenance personnel sets the keyboard password, select the keybd lok key to lock the keyboard, and then forget the password, this will cause the fault. The solution is to turn off the power of the maintenance terminal, open the base, short-circuit the two ends of the battery used for information storage, release the storage information, and restore the keyboard to normal.

3) The command input is normal. Press the RUTURN key and do not execute the command.

After the AMO command is entered, press RUTURN to run the command. Press CTRL + C to run the command. In the F500 terminal, RUTURN is not the execution key, and CTRL + C is the execution key. If the maintenance personnel selects the default key when viewing the menu, the original ruturn key is defined as CTRL + C and disappears, this failure will occur. Solution: select the edit key menu and redefine RUTURN As CTRL + C to restore normal operation.

Press CTRL + F9 to display W1 BLK or W1LOK on the screen. Press CTRL + F9 to display the W1 status. The operation key returns to normal.

3. Telephone fault

The AC is used for communication between the system and external users. It provides functions such as forwarding, forced insertion, persistence, and listening. It is a tool for operators. Common Faults include:

1) abnormal display on the telephone Console

This fault is mostly caused by software or data errors. The user station automatically disables the port and re-opens the port. Method: Execute the command ACT-DSSU: ONTYPE-AUL, PEN = telephone port number); telephone reload data, restore to normal.

2) No display on the phone desk

There are two reasons why the telephone station does not display: Power Supply and connection cable faults; and the telephone station itself faults.

Check and find that the phone is down. The 48 V Direct Current used by the telephone station. The power source is taken from the distribution frame and the corresponding insurance pop-up occurs. Find that the connected cable telephone station is not faulty, re-install the insurance, the telephone station starts loading and returns to normal.
4. User fault

HICOM uses SLMA to simulate the user board. Each Board has 16 users. User faults are the most common faults. First, the distribution frame is separated from the internal and external ends by a separator, and the test determines whether the fault is an internal city fault or an external line fault. If an external city fault occurs, an external line is processed. The specific method is not described here. Internal line faults can be divided into the following categories:

1) user ports are closed due to external line faults.

Such faults are caused by external line faults. When the external line is electrified or short-circuited, the User Detection Unit detects abnormal user status and outputs fault information on the maintenance terminal. If the fault is still not handled, the port is protected after a period of time, the system startup software automatically closes the port. In this case, after an external line fault is handled, use the command to open the port.

For example, if ext. 2000 is disabled, the port is 1-1-3-7. Enter the AMO command:
ACT-DSSU: ONTYPE = AUL, PEN = 1-1-3-7;
Or ACT-DSSU: ONTTYPE = AUL, STNO = 2000;
Sometimes the port cannot be enabled smoothly. You can use it with the opening command of the Board:
ACT-BSSU: ONTYPE = AUL, LTG = 1, LTU = 1, SLOT = 3;
The port returns to normal and the status is READE.

2) the circuit of the User Board port is damaged.
After switching and plugging the user board, the corresponding port is still not recovered. You may suspect that the fault is caused. Adjust the two user boards. If the fault occurs with the Board, the corresponding port on the user board is damaged, and the switch user board is back to normal on the backend day.

3) User Board base or backboard fault
After judging whether the user board is normal, remove the corresponding cable plug-in from the cabinet backboard and use a table to test the socket on the backboard. If the output voltage is much lower than 48 V, it indicates that the fault occurred on the base or backboard of the user board. The solution is to disable this port for a long time and disable it temporarily.

DEL-DSSU: OFFTYPE = L, STNO = 2000;

4) damaged cable connections or plug-ins
The user cabinet and distribution frame are connected by a 16-core copper cable. During inspection, remove the corresponding cable plug-in from the cabinet backplane and use a multimeter to test the socket on the backplane. If the output voltage is 48 V, the dial-up is normal, it can be determined that the cable connection or plug-in is faulty. Each user in the plug-in corresponds to a circuit, and the coil is easy to damage. If the plug-in is normal, the connection cable is faulty. The Board once experienced poor contact with the plug-in because the cables were too tight, resulting in the absence of dial-up sound on the first port of several user boards.

5 power supply faults

Power supply faults are classified into one power supply fault and two power supply faults. I will not discuss a power failure here, but will focus on the secondary power failure. There are three types of secondary power supply: PSUF, PSUC, and PSUB. Different voltages are output to different circuit boards.

1) A single frame user has no dial-up sound

One cabinet user has no dialing sound, and other users in the same cabinet are normal. Check that the PSUB indicator of the secondary power supply corresponding to the frame is off, turn off the PSUB power switch, check that the connection cable is normal, re-enable the PSUB power supply, and restore to normal.

2) Reload a cabinet without interruption

A machine fails to work normally after being reloaded for several minutes, and the interval is getting shorter and shorter. Check the power connection and interface between the Cabinet and the host to identify the fault in the peripheral cabinet. Check the peripheral cabinet group processing unit. The four user cages are normal. Check the power PSUF and find that the power screw is loose, resulting in poor contact, poor grounding, and fault. After processing, reinstall the power supply and the fault disappears.

HICOM has a complete maintenance and alarm system. Once a fault occurs, the information is immediately displayed on the maintenance terminal and can be printed out. At the same time, the fault information is saved to the file for easy search. Therefore, when dealing with faults, we should make full use of the output information to locate and find them, constantly sum up experience, and improve the maintenance and repair level.