Siemens alarm 14815: Channel %1 block %2 negative thread lead change programmed
SINUMERIK channel alarm · Siemens 840D/810D powerline
What it means
In a thread block with changing lead, the programmed change drives the instantaneous lead below zero within the block. The lead must remain positive from thread start to end. Reduce the change rate or shorten the ramp so the resulting lead stays valid.
Likely causes
- Lead-change amount too large for the block length
- Wrong sign combining increase and decrease sections
- Thread ramp ending past the physical thread
Need the part urgently?
Send us alarm 14815 with your machine details — typical RFQ turnaround is 24–48h.