---
title: "system.dnp.demandPoll"
description: "Issues a poll request for one or more classes."
---

# system.dnp.demandPoll

> Issues a poll request for one or more classes.

:::note
The following function uses [system.dnp](appendix\scripting-functions\system-dnp\system-dnp.md) and the [DNP3 driver](ignition-modules\opc-ua\opc-ua-drivers\dnp3\dnp3-driver\dnp3-driver.md). For [system.dnp3](appendix\scripting-functions\system-dnp3\system-dnp3.md) functions and the [Legacy DNP3 driver](ignition-modules\opc-ua\opc-ua-drivers\dnp3\legacy-dnp3-driver\legacy-dnp3-driver.md), see [DNP3](ignition-modules\opc-ua\opc-ua-drivers\dnp3\dnp3.md).
:::

This function is used in **Python Scripting**.

## Description

## Client Permission Restrictions

This scripting function has no [Client Permission](ignition-modules\vision\vision-project-properties\vision-project-properties.md#vision-permissions-properties) restrictions.

## Syntax

`system.dnp.demandPoll(deviceName, classList)`

### Parameters
Type | Parameter | Description 
------- | ------- | -----
String| `deviceName` | The name of the DNP3 device instance.
 List| `classList` | A List of classes (1, 2, 3) to issue polls.

### Returns
Nothing.

### Scope
Gateway

## Code Examples

```python title="Code Snippet"
system.dnp.demandPoll("DNP3", [1])
```