CONSTANT_VALUE_CHANGED

Severity: info (warn when name matches a safety-critical prefix)

A VAR_GLOBAL CONSTANT's initial value changed.

Why it matters. Constants encode design assumptions (max speed, trip thresholds, retry counts). Changing one without a note in the PR often surfaces months later as a regression. The safety-prefix bump catches the high-risk cases automatically.

Settings. safety_critical_prefixes (default: SAFETY_, INTERLOCK_, SIL_, LIMIT_, MAX_, MIN_) controls which identifiers elevate to warn.

safety_critical_prefixes:
  - SAFETY_
  - SIL_
  - EMERGENCY_

Trigger.

(* before *)                              (* after *)
VAR_GLOBAL CONSTANT                       VAR_GLOBAL CONSTANT
    SAFETY_TIMEOUT : TIME := T#2s;            SAFETY_TIMEOUT : TIME := T#10s;
END_VAR                                   END_VAR

The bot posts.

🟧 warn  CONSTANT_VALUE_CHANGED
Constant SAFETY_TIMEOUT: T#2s → T#10s
Identifier prefix matches a safety-critical pattern;
double-check the change is approved.

Fix. If documented and reviewed, suppress with disabled_checks or tune safety_critical_prefixes. Otherwise revert.