---
title: "system.opchda.isServerAvailable"
description: "Checks to see if the specified OPC-HDA server is defined, enabled, and connected."
---

# system.opchda.isServerAvailable

> Checks to see if the specified OPC-HDA server is defined, enabled, and connected.

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.opchda.isServerAvailable()`

### Parameters

| Type | Parameter | Description |
| ------- | ------- | ------ |
| String | `serverName` | The name of the OPC-HDA server to check. |

### Returns

**Boolean** - Will be true if the server is available and can be queried, false if not.

### Scope

Gateway, Vision Client, Perspective Session

## Code Examples

```python title="Example #1"
# This example will check to see if there is an OPC HDA server called "ServerName" available.
system.opchda.isServerAvailable(“ServerName”)
```