Technician I/O Diagnosis¶
Use this sequence when a signal on the HMI does not match the field.
Read The Chain In Order¶
| Step | Evidence | Next action |
|---|---|---|
| 1. HMI value | tag state, timestamp, and whether the value is stale or fresh | if stale, check runtime status first |
| 2. Runtime evidence | runtime panel, io-read, or control API result |
if runtime and HMI differ, inspect mapping and refresh path |
| 3. Mapping | config.st, io.toml, address, scaling, inversion, and task ownership |
if mapping is wrong, fix the engineering config |
| 4. Field check | sensor, actuator, terminal, fuse, or networked device state | if field and runtime differ, troubleshoot wiring or hardware |