> For the complete documentation index, see [llms.txt](https://docs.verifone.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.verifone.com/support-nordics/p400-two-piece-sa/how-tos/how-to-connect-the-devices-together.md).
# How to Connect the Devices Together
Pair your P400 Two-Piece operator unit and customer unit so they can talk to each other.
{% hint style="info" %}
**Use this when** you need to connect (pair) your operator unit and customer unit — for example, after first setting up the terminal.
{% endhint %}
To connect the two units, you'll find the **operator unit's IP address**, set the operator unit's communication settings, then enter that IP address on the **customer unit**.
## Before you start
{% hint style="warning" %}
Both units must be connected to the **same network** — see [How to Connect the Cables](/support-nordics/p400-two-piece-sa/how-tos/how-to-connect-the-cables.md).
{% endhint %}
## Operator unit — find the IP address
{% stepper %}
{% step %}
### Open the IP addresses screen
1. On the operator unit, press **#**.
2. Select **Administration > Settings > Communications**.
3. Scroll down and select **More > Status > IP addresses**.
4. Select **LAN**.
{% endstep %}
{% step %}
### Print the IP address
Press **Print** in the bottom-right corner and keep the printout — you'll need the IP address later.
Check the printout says **"UP"** under **Status**. If it doesn't, check the network cables are connected correctly and print again.
Press the **red button** until you're out of the menu.
{% endstep %}
{% endstepper %}
## Operator unit — set the communication settings
{% stepper %}
{% step %}
### Check the ECR port
1. Press **#**.
2. Select **Administration > Settings > ECR > Set ECR Port**.
3. Check it shows **9600**. If it doesn't, enter **9600**, then press the **green button**.
{% endstep %}
{% step %}
### Choose the connection
Select **Choose comm. Device** and press **Ethernet#0**. Then press the **red button** until you're out of the menu.
{% endstep %}
{% endstepper %}
## Customer unit — enter the IP address
{% stepper %}
{% step %}
### Open the menu
On the customer unit, press **4** and **6** at the same time, then enter password **1234**.
{% endstep %}
{% step %}
### Enter the operator unit's IP address
1. Select **Administration > Settings > ECR > Set ECR Address**.
2. Enter the IP address from the printout, then press the **green button**.
{% hint style="info" %}
Use the **number keys** for the digits and the **\*** button for each dot.
{% endhint %}
{% endstep %}
{% step %}
### Check the ECR port
Select **ECR Port**. Check it shows **9600**. If it doesn't, enter **9600**, then press the **green button**.
{% endstep %}
{% step %}
### Choose the connection
Select **Choose comm. Device** and press **Ethernet#0**. Then press the **red button** until you're out of the menu.
{% endstep %}
{% endstepper %}
## Test the connection
Within about a minute of leaving the menu on both units, each screen should show only the **Verifone logo on a white background**. This means the units are connected.
To double-check, make a test purchase:
1. **Operator unit:** press the **green button** and enter an amount.
2. **Customer unit:** the purchase should now show on the screen.
{% hint style="success" %}
If the purchase shows on the customer unit, your terminals are ready to use.
{% endhint %}
{% hint style="warning" %}
If the units still aren't connecting, see [Terminal Is Ready, Waiting for ECR Connection](/support-nordics/p400-two-piece-sa/errors/terminal-is-ready-waiting-for-ecr-connection.md).
{% endhint %}
Keywords
Also called: connect devices, pair terminals, pair units, connect operator and customer unit, ECR setup, set up communication. Search terms: pair, connect, IP address, ECR, ECR port, 9600, Ethernet#0, operator unit, customer unit.
---
# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.
## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation by asking a question.
Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters:
```
GET https://docs.verifone.com/support-nordics/p400-two-piece-sa/how-tos/how-to-connect-the-devices-together.md?ask=&goal=
```
`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.
Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.