What causes FANUC alarm 210?

M198 called from within a subprogram or macro (only allowed in main program). M99 used to create a repeat loop in a situation where it is prohibited. M198 called while DNC mode is not active or the external device is not ready. M99 P-number reference points to an invalid or non-existent block number. Multiple levels of M99 repeat nesting exceeded the allowed limit.

How do I fix FANUC alarm 210?

1. Move M198 calls to the main program level — it cannot be used inside subprograms. 2. Verify DNC mode is active and the external device is connected and ready before M198 executes. 3. Check M99 P-number targets are valid block numbers within the current program. 4. Review the Fanuc programming manual for allowed contexts for M198 and M99. 5. If using M99 for looping, verify the loop termination logic is correct.

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FANUC Controller

Program/G-code · Intermediate · 20-45 minutes

Alarm 210

Fanuc Alarm 210 - CAN NOT COMMAND M198/M99

Alarm 210 occurs when the CNC detects an M198 (external subprogram call) or M99 (subprogram return) command during scheduled operation mode or DNC (Direct Numerical Control) operation. These commands are incompatible with DNC/scheduled operation because they require access to the control's internal memory program structure, which conflicts with the external program feed method.

FANUCProgram/G-codeIntermediate20-45 minutes

210

Fanuc Alarm 210 - CAN NOT COMMAND M198/M99

CAN NOT COMMAND M198/M99

Root Cause Summary

Alarm 210 occurs when the CNC detects an M198 (external subprogram call) or M99 (subprogram return) command during scheduled operation mode or DNC (Direct Numerical Control) operation. These commands are incompatible with DNC/scheduled operation because they require access to the control's internal memory program structure, which conflicts with the external program feed method.

Safety

Tool position uncertain

Causes and Fixes

1
Press RESET to clear the alarm. Verify operation mode by checking SYSTEM > PARAM screen, Parameter 0020 bit 0 (DNC operation enable) and bit 6 (scheduled operation enable). If DNC mode is active, the external program feed indicator will show on the screen.
2
Remove M198 and M99 commands from the DNC program. For DNC operation, all subprogram code must be expanded inline within the main program stream, or use M98/M99 for subprograms that are pre-loaded into CNC memory before DNC starts.
3
If external subprograms are required, switch to MEM (memory) operation mode instead of DNC. Transfer complete program including all subprograms to CNC memory via RS-232, Ethernet, or memory card, then run from internal memory.
4
Verify Parameter 3107 (subprogram storage path) is correctly set if using external subprogram storage. For 0i-F/30i/31i/32i series, check Parameter 3107 bits for USB/CF card storage options. M198 may be restricted depending on this setting during certain operation modes.

DIY Feasiblehigh confidence

Call a technician if:

·Parameter corruption requiring factory reset
·Hardware communication issues with DNC interface

Prevention

Verify operation mode before running programs with M198/M99
Structure programs appropriately for intended operation mode
Regular parameter backup and verification

Common Mistakes

Running subprogram-dependent programs in DNC mode
Using M99 infinite loops in scheduled operations
Not checking current operation mode before program execution

Related Alarms

078 079 211 212

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