What causes Siemens SINUMERIK alarm 12550?

Missing DEF statement for variable or macro before use in channel %1 block %2. PROC declaration missing for subroutine or function name %3. Incorrect or undefined macro name referenced in part program. Option or licensed function not installed or activated on controller. Syntax error in macro/variable definition statement preventing proper parsing.

How do I fix Siemens SINUMERIK alarm 12550?

1. Verify DEF statements are present and declared before first use of variable/macro name %3 in the program 2. Check PROC declarations for any referenced subroutines; confirm proper syntax and spelling match usage in block %2 3. Review channel %1 program listing around the error block; compare against template programs or working examples 4. Confirm required option licenses are installed via HMI system information menu; enable option if available but disabled 5. Validate macro/function definition file paths in _N_SMAC_DEF, _N_MMAC_DEF, _N_UMAC_DEF and user-defined files (_N_SGUD_DEF, _N_MGUD_DEF, _N_UGUD_DEF) are correct

Siemens SINUMERIK codes

axismd.ai

Siemens SINUMERIK Controller

Servo/Axis · Intermediate · 30-60 minutes

Alarm 12550

Siemens 840D 12550 - Channel block name not defined or option/function not

The identifier displayed has not been defined before being used. _N_SMAC_DEF _N_MMAC_DEF _N_UMAC_DEF _N_SGUD_DEF _N_MGUD_DEF _N_UGUD_DEF Variable: DEF statement is missing Program: PROC declaration is missing

Siemens SINUMERIKServo/AxisIntermediate30-60 minutes

12550

Siemens 840D 12550 - Channel block name not defined or option/function not

Channel block name not defined or option/function not

Safety

Refer to Siemens documentation
Ensure qualified technician performs repairs

Common Causes

Missing DEF statement for variable or macro before use in channel %1 block %2
PROC declaration missing for subroutine or function name %3
Incorrect or undefined macro name referenced in part program
Option or licensed function not installed or activated on controller
Syntax error in macro/variable definition statement preventing proper parsing

Troubleshooting Steps

1Verify DEF statements are present and declared before first use of variable/macro name %3 in the program
2Check PROC declarations for any referenced subroutines; confirm proper syntax and spelling match usage in block %2
3Review channel %1 program listing around the error block; compare against template programs or working examples
4Confirm required option licenses are installed via HMI system information menu; enable option if available but disabled
5Validate macro/function definition file paths in _N_SMAC_DEF, _N_MMAC_DEF, _N_UMAC_DEF and user-defined files (_N_SGUD_DEF, _N_MGUD_DEF, _N_UGUD_DEF) are correct

Seeing Multiple Alarms?

Seeing another alarm with this one? Enter the code.

Get machine-aware diagnosis

AxisMD logs alarms against your actual machines, tracks patterns, and gives AI context your manual doesn't have.

Start free

Was this guide helpful?

Always verify with your machine manual or a certified technician before performing service procedures.