---
title: "EMS site: Meters, Controller and Diagnostics"
url: "https://ensights.productfruits.help/en/article/ems-site-meters-controller-and-diagnostics"
language: "en"
last_updated: "2026-08-25T16:20:51.367Z"
---

# EMS site: Meters, Controller and Diagnostics

The engineering tabs: meter channels and quality, the agent that carries the commands, and AI-assisted device diagnostics.

*Fleet Management → EMS Sites → a site → Meters / Controller / Diagnostics*

## Meters

Everything the site's meters report. On the left is the meter list with **Select All Meters**, so a site with several meters can be read together or one at a time.

The chart works like the others — metric chips (Power and the rest of the channels), a granularity selector, a settings gear and a CSV download.

### The quality panel

To the right, two tables summarise the electrical channels for the period:

-   **Voltage (kV)** — one row per channel (V12, V23, V31, V1, V2, V3) with **Last Read**, **Min**, **Max**, **Avg** and **Variance**.
-   **Current (A)** — the same for I1, I2, I3.

These are the fastest way to catch a wiring or phase problem: an unbalanced set of currents, or a phase voltage that never moves, shows up here long before it shows up in energy totals.

### The interval table

Below the chart, the raw readings: **Date**, **Power**, **Voltage**, **I1**, **I2**, **I3**, **Periodic Energy Import** and **Periodic Energy Export**. This is the table to export when an off-taker or grid operator queries a reading.

## Controller

The controller tab shows the **agent** assigned to the site — the on-site device that carries commands to the equipment and readings back. When none is assigned it says plainly: *No agent is assigned to this site.*

That message explains a whole class of symptoms: a site stuck at *Pending* on the EMS list, policies that save but never take effect, a Live tab that will not render. Without an agent there is no path to the equipment. Agents themselves are managed under **Monitoring & Control → Agents**, where you can see their status, resources and network, fetch logs and restart them.

![The Controller tab when no agent is assigned](https://cdn-assets.productfruits.com/094d2f9b-6a51-4839-a8b6-c5d0b3f47f8b)

## Diagnostics

Diagnostics collects logs from the site's IoT device and has AI analyse them. The flow is shown on the page in three steps:

1.  **Command sent to device**
2.  **Logs collected**
3.  **AI analyzes & reports**

**Run Diagnostics** starts it. **Auto-refresh** keeps the page updating while it works, and **Report History** on the left keeps every previous run, so you can compare a device's health before and after an intervention.

![The Diagnostics tab with its report history](https://cdn-assets.productfruits.com/6e9e6dc7-0f6e-49e6-b3bc-0041d10984ad)

The report names the issues found, assesses performance and recommends actions. Use it before escalating to your integrator — it usually turns "the site is not responding" into a specific fault, and the report is something you can attach to the ticket.

## Common tasks

**Diagnose a site that will not respond.** Controller first (is there an agent?), then Diagnostics → Run Diagnostics, then the Agents page for the device's own status.

**Check a meter before a billing dispute.** Meters → set the period → read the Voltage and Current tables for anomalies → export the interval table.

**Catch a phase problem.** Compare I1, I2 and I3 in the Current table. A persistent imbalance is worth a site visit.

**Build a history for a flaky device.** Run diagnostics whenever it misbehaves; Report History becomes the evidence trail.

## Common questions

**Diagnostics returns nothing.**  
The device must be reachable to send logs. If the agent is offline, diagnostics cannot run — start with the Agents page.

**Do I need an agent for every EMS site?**  
Yes, for control. Monitoring can work through a vendor integration, but commands need an on-site agent.

**The meter chart is empty but the interval table has rows.**  
No metric is selected in the chip field, or the chosen channel is not reported by the selected meter.