# Volt DIO

> The Volt DIO, the Voltmasters digital IO module: 6 digital inputs and 6 relay outputs, adding it on the platform and assigning its ports.

Source: https://voltmasters.io/en/docs/device-integrations/io-modules/volt-dio/

With a relay output the EMS switches an external circuit on or off. With a digital input it reads the position of an external contact. What you use the Volt DIO for is listed under [Applications](https://voltmasters.io/en/docs/device-integrations/io-modules/#applications).

## Adding the Volt DIO on the platform

1.  Add a device of the type **IO Extension**.
2.  Choose **Modbus TCP** as the connection and fill in the **IP address**, the **port** and the **Modbus slave ID** of the module, as you noted them during placement.
3.  Set the device to **managed**. A device set to *unmanaged* is only read: the EMS then never switches its relay outputs.

## Assigning ports

You assign a function to a port where that function is configured. The device’s **Ports** page shows the function and the setting of each port.

| Function | Port | Where you assign it |
| --- | --- | --- |
| **Switching a controllable load** | Relay output | When adding the load, see [Controllable loads](https://voltmasters.io/en/docs/device-integrations/controllable-loads/) |
| **Executing an emergency stop** | Relay output | DSO RTU settings, see [Emergency stop](https://voltmasters.io/en/docs/dso-rtu/emergency-stop/) |
| **Reading an emergency stop signal** | Digital input | DSO RTU settings, see [Emergency stop](https://voltmasters.io/en/docs/dso-rtu/emergency-stop/#triggering-an-emergency-stop-digital-input) |
| **Sending the position of a breaker to the grid operator** | Digital input | DSO RTU settings, see [Grid operators](https://voltmasters.io/en/docs/dso-rtu/grid-operators/) |
| **A watchdog from or to the grid operator** | Digital input or relay output | DSO RTU settings, see [ORES](https://voltmasters.io/en/docs/dso-rtu/grid-operators/ores/) |
| **Microgrid signals, such as the position of the grid breaker or the start of the generator** | Digital input or relay output | Microgrid settings, see [IO roles](https://voltmasters.io/en/docs/microgrid/configuration/#io-roles) |

A port carries one function: an output that carries an emergency stop or a watchdog cannot switch a controllable load. An input without a function is only read and logged. An output without a function stays free.

![Voltmasters EMS: the Ports page of an IO extension, with numbered markers at the inputs, the relay outputs, the function of a port and the per-port overview](https://voltmasters.io/assets/docs/io-extension-ports-emergency-stop-tour.webp)

1.  The digital inputs (**Inputs**).
2.  The relay outputs (**Outputs**).
3.  The function a port carries, here **Telecontrol emergency Production** on output 7.
4.  The per-port overview, with the **Assignment** and the **Configuration**.

## Manual override

You can set a relay output manually to **On** or **Off**, for example during commissioning or maintenance. The override takes precedence over the control. Clear it to let the port switch automatically again.

## Deleting the Volt DIO

As long as a port carries a function, you cannot delete the Volt DIO. The platform shows which ports are in use and links to the **Ports** page so you can free them first.

## Next steps

[Placement and cabling](https://voltmasters.io/en/docs/device-integrations/io-modules/volt-dio/placement-and-cabling/): Where the module goes and how to wire a relay and an input.

 

[Technical specifications](https://voltmasters.io/en/docs/device-integrations/io-modules/volt-dio/technical-specifications/): What the relays may switch, the inputs, the network and the failsafe behaviour.