PLC fault diagnosis
The alarm is gone.
Why is the line still stopped?
Follow one restart investigation, from a recorded incident to the condition that blocks the machine.
Illustrative incident
Fictional machine and recorded data. Explore the diagnosis step by step.
Restart requested.
Machine still stopped.
StoppedThe recorded sequence
- Fault raised
The machine stops.
- Alarm cleared
The visible fault is gone.
- Restart requested
The machine remains stopped.
The agent gathers the matching PLC program and recorded signals, then traces the conditions behind the unsuccessful restart.
Which condition
blocks the restart?
Select a condition to inspect its evidence.
All
required
required
Restart permitFalseFrom recorded inputs
The alarm is cleared and the drive is ready. Downstream readiness is still false.
Diagnostic caseInvestigation complete
Downstream readiness
is blocking restart.
The agent identifies the unmet PLC condition and delivers the evidence needed to understand the stoppage.
- Established
- DownstreamReady is false at the rejected restart request. The program requires it to be true.
- Still unknown
- The signals do not establish why the downstream machine is not ready. That physical cause needs further evidence.
- Evidence retained
- Matching program revision, timestamped signal values and the event sequence.