---
title: Add or edit a shared Modbus TCP gateway in Boss’nX
description: "Declare a Modbus TCP access in Boss’nX: IPv4 address, port 502 or another, CannX gateway and activation, then save and review the stored parameters."
canonical: https://wiki.can-nx.com/en/guides/boss-modbus-gateway-create/
language: en
product: Boss’nX
audience:
  - administrateur
  - installateur
context: "Boss’nX, supervision on a computer: Menu → Modbus gateways, with the Manage Modbus right"
---

# Add or edit a shared Modbus TCP gateway in Boss’nX

Context: Boss’nX, supervision on a computer: Menu → Modbus gateways, with the Manage Modbus right

In Boss’nX, a Modbus gateway describes a shared Modbus TCP access: its IPv4 address, its port and the CannX gateway that must reach it. It is then used by the components’ Modbus datapoints and by the metering configurations of the data logging.

Intended for administrators and installers. To duplicate, disable or delete a gateway, follow [Modbus gateway management](https://wiki.can-nx.com/en/guides/boss-modbus-gateway-manage/).

## Before you start

- Your role has the **Manage Modbus** right. A viewing account is not enough.
- The installation’s parameters are confirmed: IPv4 address, Modbus TCP port and the CannX gateway that must reach this access.
- For an existing entry, check the uses concerned before editing it: a gateway can be shared by Boss’nX datapoints and metering configurations.

## Open the form

1. Open the supervision you want, directly or from hypervision.
2. On a computer, choose **Menu → Modbus gateways**, in the **Integration** family; if it is folded, click its title first.
3. To add an entry, click **New gateway** above the list. The form appears on the right.
4. To edit an entry, click its row on the left: the **Edit gateway** panel shows its parameters. Check the name before making any change.

If a form is already open and you want to start another creation or a duplication, first click **Cancel**, then open the action you want. **Cancel** discards the pending changes; after **Save**, going back to the old parameters requires a new edit followed by a save.

## Fill in the address, the port and the CannX gateway

| Field | Value to provide |
| --- | --- |
| **Name** | A non-empty label that lets you recognize the access, for example **Test boiler room**, a fictional example. |
| **IP Address** | The confirmed IPv4 address of the Modbus TCP access, without spaces. A host name is not accepted instead of this address. |
| **Port** | An integer from **1 to 65535**. Creation suggests **502**; keep or change this value according to the actual configuration. |
| **CannX Gateway** | The gateway planned by the installer. The options show its name and its MAC. Check this choice even if a first option is already suggested. |
| **Enabled** | Check according to the planned use. The consequences of disabling are described in [Modbus gateway management](https://wiki.can-nx.com/en/guides/boss-modbus-gateway-manage/). |

The **CannX Gateway** list offers the project’s CannX gateways, whether they are online or not. If no CannX gateway is offered, have the project and its attachment checked rather than choosing another device at random.

## Save the gateway

1. Click **Save**.
2. Wait for **Saved successfully.** and for the form to close.

To abandon before saving, click **Cancel**. To correct a value that has already been saved, reopen the entry, change the field you want and save again.

## Check the result

1. Find the entry in the list, then click its row to review the name, the address, the port, the CannX gateway and **Enabled**.
2. Saving the parameters does not test communication with the hardware: then check that the associated datapoints or configurations work, following the installation’s procedure.

Declaring the gateway creates no datapoint. To use it in a component, then add [a Modbus datapoint](https://wiki.can-nx.com/en/guides/boss-point-modbus/). To define the measurements to read on this access, follow [the Modbus data logging configurations](https://wiki.can-nx.com/en/guides/boss-modbus-config/).

## Troubleshooting

| Message | Action |
| --- | --- |
| **This field is required.** | Fill in the missing name or CannX gateway. |
| **Invalid IP address.** | Check the four numbers of the IPv4 address and remove the spaces. |
| **Invalid port (1–65535).** or a browser validation refusal | Enter the confirmed integer port, within this range. |
| **You don't have permission to view this page** | Have the **Manage Modbus** right checked on your role. |
| **Error while saving.** | Note the message and the fields concerned. Check the list before trying again. |

If the **Modbus gateways** entry is missing from the **Menu**, check the same right, the supervision context and the **Integration** family, which may be folded.

If the save seems to have succeeded but the row is missing, first clear the list’s search, then leave and reopen **Modbus gateways**. Do not immediately recreate an identical entry.

If the situation remains uncertain, contact support@can-nx.com with the supervision, the entry name, the message and your attempts. No password or private link is needed.

French labels: **Menu → Passerelles Modbus**, **Intégration**, **Nouvelle passerelle**, **Modifier la passerelle**, **Nom**, **Adresse IP**, **Port**, **Passerelle CannX**, **Activée**, **Enregistrer**, **Annuler**, **Enregistré avec succès.**