ALARMSMazatrol Assistant
CRITICALAlarm code
1821

UNWRITABLE SYSTEM VARIABLE (WNo., NNo., BNo.)

What it means

Writing into a write-protected system variable has been attempted.

What to do
  1. 1Correct the program.
Codebook — decoded
BError typeRegistered Data — program or tool data error
I (L)Stop statusunspecified
O (S)Clearingunspecified
Still faulted after these steps? Do not restart under load — ask the Mazatrol assistant.
Still stuck? Ask the Mazatrol assistant →