OPC-DA collector
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
Node
Description: The node of the OPC-DA server. Required: yes Default: localhost
This setting was called Nodes and accepted a comma separated list before collector version 3.0.0, which removed support for multiple OPC-DA servers. A collector upgraded from an earlier version keeps only the first node of the old list.
CollectionSource
Description: The source from which to collect data. Required: yes Options: Cache | Device Default: Cache
Advanced settings
EscapeNonPrintableCharacters
Description: When enabled, every string value read from the OPC-DA server is quoted and its non-printable characters are escaped before it is stored. Turn this off to store the raw string. Required: no Default: true
HeartBeatInterval
Description: The interval in milliseconds of the liveness probe that decides when the connection is declared dead and the collector reconnects. This is the mechanism behind the OPC-DA server unavailable health message. Required: no Default: 10000 Minimum: 5000
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
Checkout the data collection methods 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. The measurement is polled at its own collection interval, raised to the minimum of 1000ms if configured lower, and each sample is compared against the last stored value; unchanged samples are dropped. A change that happens between two polls is therefore not seen, so keep the collection interval short enough for the changes you care about. 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 herehere 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 connecting to OPC-DA server
The collector failed to connect to the OPC-DA server. This indicates that a collector setting hasn’t been configured correctly or that the OPC-DA server isn’t reachable.
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.