Siemens SINUMERIK codes
Siemens SINUMERIKServo/AxisIntermediate30-60 minutes

16955

Siemens 840D 16955 - Channel stop in stop delay area is delayed

Channel stop in stop delay area is delayed

In a program area (stop delay area) that is bracketed by DELAYFSTON and DELAYFSTOF, an event has been detected that causes a stop. The stop is delayed and executed after DELAYFSTOF. A stop delay area can also be defined by $MN_STOP_MODE_MASK.

Safety

  • Refer to Siemens documentation
  • Ensure qualified technician performs repairs

Common Causes

  • Stop command issued during active DELAYFSTON/DELAYFSTOF block without proper sequencing
  • Conflicting stop delay parameters in $MN_STOP_MODE_MASK configuration
  • Motion commands extending beyond intended stop delay area boundaries
  • PLC or external stop signal timing overlapping with delay zone execution
  • Improper NC program logic with nested or overlapping stop delay regions

Troubleshooting Steps

  1. 1Verify DELAYFSTON and DELAYFSTOF block placement in NC program matches intended stop delay area; confirm blocks are properly paired without nesting conflicts
  2. 2Review $MN_STOP_MODE_MASK parameter settings on the affected channel and cross-reference against machine documentation for correct bit configuration
  3. 3Check program flow around stop command insertion point; ensure stop is not being triggered during active delay zone or immediately after DELAYFSTON
  4. 4Inspect PLC interface logic and external stop signal timing; verify no competing stop commands are being issued within the delay area window
  5. 5Simulate program execution in dry-run or single-block mode to observe actual stop timing versus expected stop point; adjust DELAYFSTOF placement if stop is occurring at unintended location

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