---
title: OPC-DA collector
slug: opc-da-collector
createdAt: 2025-09-09T09:35:38.514Z
---

## Basic settings

The collector settings are used by the collector to connect to the OPC-DA server.

### ProgID

**Description**: The programmatic identifier of the OPC-DA server.
**Required**: yes
**Example**: Matrikon.OPC.Simulation.1

### Nodes

**Description**: The nodes of the OPC-DA server separated by commas.
**Required**: yes
**Default**: localhost

### CollectionSource

**Description**: The source from which to collect data.
**Required**: yes
**Options**: Cache | Device
**Default**: Cache

## Measurement settings

The measurement settings reflect the configuration possibilities for mapping a measurement to an OPC-DA tag.

### ItemID

**Description**: Fully qualified OPC-DA item name.
**Required**: yes
**Example**: Factry.Saw-1

### CollectionType

**Description**: The way this measurement should be collected from the OPC-DA server.
**Required**: yes
**Default**: polled
**Options**: polled | monitored

:::hint{type="info"}
Checkout the [data collection methods](docId\:KxvcVYI7pr5w-bDSjK1hQ) section for more information.
:::

### CollectionInterval

**Description**: The interval in milliseconds at which this measurement should be collected.
**Required**: yes
**Default**: 5000

### CollectionOffset

**Description**: The offset in milliseconds, relative to the 0th second of a minute, at which this measurement should be collected. Only relevant for polled measurements.
**Required**: yes
**Default**: 0

## Data collection methods

The OPC-DA collector has 2 methods to collect measurement data, which are referred to as the collection type of a measurement.

### Polling

Polled measurements are read every x milliseconds (minimum of 1000ms), which is the collection interval. This data collection method should be used for measurements for which the value changes regularly over time. Configure the interval depending on how frequent you want to collect data points for this measurement.

### Monitoring

Monitored measurements collect data on every change of the measurements value. This data collection method polls the measurement at the minimum interval and notifies the collector whenever a change occurs. Typically, monitored measurements are configured for boolean or string data types that indicate an equipments state, f.e. for a valve that opens and/or closes only a few times per hour.

## Collector health

OPC-DA Specific collector health messages. See [here](docId\:CUxTvhAhQ2yyJjjwAtDH8) for all generic collector health messages.

You can find the collector health and the collector health history in the detail view on the right, when selecting a collector in the historian admin webpage.

### Error initializing OPC-DA client

An error occurred while trying to initialize the OPC-DA client. This indicates that a collector setting hasn’t been configured correctly or that the OPC-DA server isn’t reachable during initialization.

### OPC-DA server unavailable

The OPC-DA client lost connection with the OPC-DA server.

## Limitations

It is currently not possible to read arrays from the OPC-DA server.