> For the complete documentation index, see [llms.txt](https://vesta-guide.gitbook.io/vesta-guide/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://vesta-guide.gitbook.io/vesta-guide/tips-and-help/quick-guide-correct-connection-of-optex-barriers-with-a-wireless-transmitter.md).

# Quick Guide - Correct connection of OPTEX barriers with a wireless transmitter

### Connection procedure

#### 1. Identify the 2-pin cable

The barrier transmitter has a **2-pin cable with a blue wire and a green wire**.

This cable is normally used for **tamper** or **battery low** reporting.

If you do **not** use that function, use this cable for the barrier **GND** connection.

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#### 2. Connect the cable to the BCU-5 receiver

Connect the 2-pin cable to the **power connector on the BCU-5 receiver**.

* **Blue wire → GND**
* **Green wire → Not used**

<figure><img src="/files/ddvbBbIsYWBzhG3vQsf9" alt="" width="563"><figcaption></figcaption></figure>

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#### 3. Connect the GND to the wireless transmitter

Connect the **blue wire** to the **GND terminal** of the wireless transmitter.

Connect it together with the **yellow ALARM NC wire**.

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### Wiring diagram

<figure><img src="/files/li6ebgqqqNHUBPGtme2a" alt=""><figcaption></figcaption></figure>

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### Result

The barrier and the wireless transmitter now share the same **GND**.

This ensures correct and reliable operation.