axismd.ai
Siemens SINUMERIK Controller
Servo/Axis · Intermediate · 30-120 minutes
Siemens 4112 - Servo cycle changed to ms
Alarm 4112 indicates that the servo cycle time (MD 10060 POSCTRL_SYSCLOCK_TIME_RATIO) has been automatically recalculated due to a modification of the PROFIBUS DP cycle time stored in SDB-Type-2000 parameter MD 10050 SYSCLOCK_CYCLE_TIME. This automatic adjustment ensures synchronization between the NCK servo control loop and the PROFIBUS DP communication cycle on 840D systems.
4112
Siemens 4112 - Servo cycle changed to ms
Servo cycle changed to ms
For PROFIBUS/PROFINET only: MD10060 $POSCTRL_SYSCLOCK_TIME_RATIO has been modified because of the modified DP cycle in the SDB (MD10050 $SYSCLOCK_CYCLE_TIME) Control reaction: Alarm display.
Root Cause Summary
Alarm 4112 indicates that the servo cycle time (MD 10060 POSCTRL_SYSCLOCK_TIME_RATIO) has been automatically recalculated due to a modification of the PROFIBUS DP cycle time stored in SDB-Type-2000 parameter MD 10050 SYSCLOCK_CYCLE_TIME. This automatic adjustment ensures synchronization between the NCK servo control loop and the PROFIBUS DP communication cycle on 840D systems.
Safety
- Drive/power/encoder circuit: hazardous voltages may remain in the DC link after power-off. Lock out / tag out, wait for discharge per the drive documentation, and use qualified personnel only.
Causes and Fixes
- 1
Navigate to Diagnostics > Parameters > Machine Data on the 840D control. Locate MD 10050 SYSCLOCK_CYCLE_TIME to verify the current DP cycle time value.
- 2
Check MD 10060 POSCTRL_SYSCLOCK_TIME_RATIO to confirm the new servo cycle ratio. Document the previous value from system commissioning records or machine documentation.
Do not manually override MD 10060; the system auto-adjustment ensures proper NCK/PROFIBUS synchronization.
- 3
Verify SDB-Type-2000 parameters in the PROFIBUS configuration (accessible via HMI > Configuration > Communication or through STEP 7 if integrated). Confirm DP cycle settings match the intended machine configuration.
- 4
If the DP cycle change was unintended, restore the previous SDB-Type-2000 configuration and perform a cold start (POWER ON/OFF cycle) to reset MD 10060 to its original ratio.
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 freeWas this guide helpful?
Always verify with your machine manual or a certified technician before performing service procedures.