FANUC system black screen alarm ALM197 alarm solution

There are two types of FANUC system screens, one is the black screen, and the other is the operation screen we normally enter. When the system detects that it cannot maintain the normal operation of the system, it will transfer to the system alarm screen, collectively referred to as the black screen.

When entering the system alarm state, the system will:

• Disconnect the excitation of the servo and spindle amplifier

• Cut off the communication of the I/O LINK

When a system alarm occurs, it switches to the screen shown below, which is called the system alarm screen. In this screen, the system tells us the cause of the fault and the direction to solve the problem.

System alarms can be divided into the following 3 types.

• Alarms detected by software

• Alarms detected by hardware

• Other alarms

Alarms detected by software

The CNC system software mainly detects software abnormalities. Typical causes of abnormality are:

• Detection of process/data inconsistency based on internal status monitoring software

• Access outside the data/command range

• Division by zero

• Stack overflow

• Stack underflow

• DRAM sum check error

Alarms detected by hardware

Hardware abnormalities are mainly detected by hardware. Typical abnormal reasons are:

• Parity error (DRAM, SRAM, ultra-high-speed cache)

• Bus error

• Power alarm

• FSSB cable disconnection

Other alarms

Other reasons are:

• Alarms detected by peripheral software

• Servo software (watchdog, etc.)

• PMC software (I/O LINK communication abnormality, etc.)

Black screen alarm ALM_197 case sharing 1

Observe the above alarm information, the format is as follows:

SYS_ALM197 EMBEDDED SOFTWARE SYSTEM ERROR

CPU CARD

Fault cause: IO LINK communication error

Case cause: IO board JD1B K5 plug poor contact, resulting in the above alarm

Black screen alarm ALM_197 case sharing 2

Observe the above alarm information, the format is as follows:

SYS_ALM197 EMBEDDED SOFTWARE SYSTEM ERROR

PC050 IO LINK ER1 CHz:GRyy:xx

Check the maintenance manual, the explanation is as follows:

Cause of failure: IO LINK communication error

Possible causes:

1. Momentary disconnection of slave device, voltage fluctuation, power cable

2. Bad communication cable, bad connection

3. Slave device failure

The general meaning is

1. Bad 24VDC power supply or 24V short circuit

2. Bad signal line from I/O to system panel

3. Bad ROM board