# Capturing Measurements

Once you have configured the [connection](rhopoint-com-agent-connecting-an-instrument.md) and chosen your [output](rhopoint-com-agent-output-formats.md), you are ready to capture.

## Start and stop

Press **Start** (top right). COM Agent opens the serial port and begins listening. The button turns into **Stop**; press it to end the session and release the port.

While capture is running, the configuration on the left is **locked** so it cannot be changed mid-session.

<!-- docshot: running -->
![](../_images/com-agent-running.png)

## The live panel

The right-hand side shows what is happening in real time:

| Element | Meaning |
| --- | --- |
| **Status badge** | **Idle** before you start, **Listening** while capturing, **Error** if the connection fails. |
| **Received Sets** | A running count of complete measurements captured in this session. |
| **Last Measurement** | The Mean, Minimum, Maximum and Std Dev of the most recent measurement (for recognised formats). |
| **Activity Log** | A scrolling list of events: data received, files written (with their full path), keyboard output, and any warnings. Use **Clear** to empty it. |

## Taking a measurement

1. Press **Start** in COM Agent.
2. Trigger a measurement on the instrument as you normally would.
3. The activity log shows *"Receiving data…"* followed by the path of each file written, or a *"[Keyboard]"* entry if keyboard emulation is enabled.
4. The **Received Sets** counter increases and **Last Measurement** updates.

> [!info] Each completed measurement is handled independently — you can take as many as you like in one session. There is no need to stop and start between measurements.

> [!warning] If the status changes to **Error** (for example, the cable is unplugged or the instrument is switched off), stop the session, check the connection, and start again.

[Next: try it without an instrument](rhopoint-com-agent-demo-mode.md)