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Siemens SINUMERIK Controller
Program/G-code · Intermediate · 30-120 minutes
Siemens 10221 - [up to SW 3.x only] Channel not stopped at end of block
Alarm 10221 occurs on older SINUMERIK 840D systems (SW 3.x and earlier) when a channel fails to reach a complete stop at the end of a programmed block where a stop is expected. This typically happens due to timing conflicts between rapid block changes, feedrate override issues, or synchronization problems in multi-channel machining operations.
10221
Siemens 10221 - [up to SW 3.x only] Channel not stopped at end of block
[up to SW 3.x only] Channel not stopped at end of block
The reorganization of NC blocks starting at the current block (REORG) is only possible at the end of the block Control reaction: Alarm display.
Root Cause Summary
Alarm 10221 occurs on older SINUMERIK 840D systems (SW 3.x and earlier) when a channel fails to reach a complete stop at the end of a programmed block where a stop is expected. This typically happens due to timing conflicts between rapid block changes, feedrate override issues, or synchronization problems in multi-channel machining operations.
Safety
- Only qualified personnel should diagnose and clear control alarms; follow the machine builder's safety procedures and lockout/tagout where hardware work is required.
Causes and Fixes
- 1
Review the NC program at the alarm occurrence point for rapid block changes, particularly around synchronized actions (WAITM, WAITP) or exact stop commands (G60, G9).
- 2
Temporarily reduce feedrate override to 50-75% and test the program to determine if timing is the issue.
- 3
Insert explicit G60 (exact stop) or G9 (exact stop non-modal) commands one or two blocks before critical synchronization points.
- 4
Check machine data MD20200 $MC_PROG_FEEDRATE_PER_REV_SOURCE and MD20150 $MC_GCODE_RESET_VALUES for proper stop mode configuration and adjust if necessary.
Modifying machine data requires backup and may affect other programs - consult machine OEM documentation
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