Troubleshooting (Trend)

Plot any signal, zoom into an incident, and see which signals left their normal pattern first. Add what the crew saw, and confirm or reject each lead.

In the Suite, this module appears as Trend & troubleshooting, at platform.beedy.ca/trend/.

What it does

It is a historian view built for finding causes. Every signal is stored on the server; the chart shows it, and the analysis ranks what moved first during an incident. The computation runs on the server; your browser only displays the results.

First steps

1. Open the page. The default signals are effluent ammonium (EFF_NH4), bioreactor dissolved oxygen (BIO_DO) and influent flow (FLOW_INF).
2. In the Signals tree on the left, click a signal to plot it. Up to six signals show at once; adding a seventh drops the oldest.
3. Choose a time range: 6 h, 24 h, 72 h, 7 d or All, or Follow live. Drag to pan, scroll to zoom, click to pick a moment.

Working an incident

Incidents and maintenance appear as shaded bands behind the chart, and are listed under it. Click one: the chart zooms to the incident plus four hours either side, loads the signals that matter, and runs What moved first.

The panel lists each signal that departed from its normal pattern, in order, with its direction and its distance from normal in standard deviations (σ). Why? next to a signal shows what moved before that one.

How it decides: each signal is compared with its own pattern over the previous three days, re-levelled to the last 12 hours. A departure starts when the 30-minute median passes 3σ, or when a limit is breached. To be named as a likely cause, a signal must reach 5σ.

Crew observations

Operators see, hear and smell things instruments don't. Click the chart at the moment, then Add observation: choose the asset (or the whole plant), the kind (saw, heard, smelled, manual action, lab result, field reading, other) and describe it in up to 600 characters. Notes show on the chart and in the timeline. A note made before any signal moved is marked Noted before any signal moved.

Verdicts

Next to each lead, mark Confirmed or Not the cause. Verdicts are recorded with your role, and others see them. They are passed to OTIS when he explains the incident.

Sharing a view

The address bar keeps the view: #tags=BIO_DO,EFF_NH4 opens those signals, #event=last opens the latest incident. Copy the link to share exactly what you see.

Troubleshooting the troubleshooter

• No incident in view: widen the range to 72 h or 7 d; incidents are 18 to 34 plant hours apart.
• A signal looks flat: some signals are held by a control loop (for example sludge age or effluent phosphorus); they are judged against a flat baseline and move only when control is lost.
• Your notes disappeared: your sandbox expires 48 hours after your last activity, or when you clear cookies.