---
title: "system.opchda.readAttributes"
description: "Reads the specified attributes for the given item over a time range."
---

# system.opchda.readAttributes

> Reads the specified attributes for the given item over a time range.

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

## Description
Reads the specified attributes for the given item over a time range. Attributes and their IDs are defined in the OPC-HDA specification, and can be discovered by calling [system.opchda.getAttributes()](appendix\scripting-functions\system-opchda\system-opchda-getAttributes.md).

## 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.readAttributes(serverName, itemId, attributeIds, startDate, endDate)`

### Parameters
Type | Parameter | Description 
------- | ------- | ------
String| `serverName` | The name of the defined OPC-HDA server to read.
String| `itemId` | The itemID to retrieve attributes for.
List[String]| `attributeIds` | The integer IDs of the attributes to read. The attribute ids are defined in the OPC-HDA specification. The attributes can also be obtained by calling [system.opchda.getAttributes()](system-opchda-getAttributes.md). Some servers may not support all attributes.
String (can be other data types, such as int)| `startDate` | The starting date/time of the query.
String (can be other data types, such as int)| `endDate` | The ending date/time of the query.

### Returns
**List[ReadResults]** - A list of read results which is one-to-one with the requested attributes. The ReadResult object has a serviceResult quality property that indicates whether the call was successful, and it is itself a list of QualifiedValues.
### Scope
Gateway, Vision Client, Perspective Session

## Code Examples
```python title="Example #1"

# This example will get user-specified attributes over a period of time from a Matrikon OPC HDA explorer.
# Declare start and end dates
start = system.date.getDate(2022, 10, 24)
end = system.date.getDate(2022, 10, 24)
 
# Call the system function
hda = system.opchda.readAttributes('Matrikon HDA','1',[1],start,end)
print hda
```