Yaskawa MP2300S Basic Module - Manual (Page 321)

9.4 Troubleshooting Details
9.4.3 Watchdog Timer Timeout Errors
9-10
9.4.3 Watchdog Timer Timeout Errors
If a watchdog timer timeout error occurs, one of the following may be the cause.
• An infinite loop has occurred in a user program.
• A scan time over has occurred in a user program.
• A motion module *1 has failed.
• A watchdog timer timeout error has occurred in an MPU-01 Module.
*2
* 1. Motion modules: PO-01, SVA-01, SVB-01, SVC-01, MPU-01
* 2. If a watchdog timer timeout error occurs when using an MPU-01 module, refer to 6. Troubleshooting in the
Machine Controller MP2000 Series MPU-01 Multiple-CPU Module User's Manual (manual number: SIEP
C880781 05).
If a watchdog timer timeout error occurs, it is important to identify whether the cause is the CPU module itself or
another motion module.
To identify the cause, cycle the power with the CPU module program stopped and check if the problem has changed.
If a watchdog timer timeout error does not occur after the CPU module program has been stopped, the problem is prob-
ably in the CPU module. Check if the program has any infinite loops in it.
If the problem remains, the motion module may have failed. Contact your Yaskawa representative.
9.4.4 Module Synchronization Errors (Ver. 2.75 or Later)
If a module synchronization error occurs, one of the following may be the cause.
• A motion module *1 has failed.
• A watchdog timer timeout error has occurred in an MPU-01 module. *2
* 1. Motion Modules: PO-01, SVA-01, SVB-01, SVC-01, MPU-01
* 2. If a module synchronization error occurs when using an MPU-01 module, refer to 6. Troubleshooting in the
Machine Controller MP2000 Series MPU-01 Multiple-CPU Module User's Manual (manual number: SIEP
C880781 05).
If a module synchronization error occurs (SW00050 = 00051H), the module synchronization error detection slot will
be reported in the system registers as shown in the following table.
* Module synchronization errors are reported for CPU system software version 2.75 or later.
For version 2.74 or earlier, it is reported as a watchdog timer timeout error.
If a module synchronization error has occurred, contact your Yaskawa representative.
When the power is cycled with the STOP switch on the front of the
CPU module set to ON, the CPU module will start with execution
of the CPU module ladder program stopped.
STOP
SUP
INIT
CNFG
MON
TEST
SW1
OFF ON
1 2 3 4 5 6
Register No. Description
SW00076
Module synchronization error detection slot *
††yyH ††: Rack number (01 to 04) yy: Slot number (01 to 09)