# OPC UA Client Reader Input Plugin

This plugin gathers data from an [OPC UA][opcua] server by subscribing to the
configured nodes.

⭐ Telegraf v1.16.0
🏷️ iot
💻 all

[opcua]: https://opcfoundation.org/about/opc-technologies/opc-ua/

## Global configuration options <!-- @/docs/includes/plugin_config.md -->

In addition to the plugin-specific configuration settings, plugins support
additional global and plugin configuration settings. These settings are used to
modify metrics, tags, and field or create aliases and configure ordering, etc.
See the [CONFIGURATION.md][CONFIGURATION.md] for more details.

[CONFIGURATION.md]: ../../../docs/CONFIGURATION.md#plugins

## Secret-store support

This plugin supports secrets from secret-stores for the `username` and
`password` option.
See the [secret-store documentation][SECRETSTORE] for more details on how
to use them.

[SECRETSTORE]: ../../../docs/CONFIGURATION.md#secret-store-secrets

## Configuration

```toml @sample.conf
# Retrieve data from OPCUA devices
[[inputs.opcua]]
  ## Metric name
  # name = "opcua"

  ## OPC UA Endpoint URL
  # endpoint = "opc.tcp://localhost:4840"

  ## Maximum time allowed to establish a connect to the endpoint.
  # connect_timeout = "10s"

  ## Maximum time allowed for a request over the established connection.
  # request_timeout = "5s"

  ## Maximum time that a session shall remain open without activity.
  # session_timeout = "20m"

  ## Retry options for failing reads e.g. due to invalid sessions
  ## If the retry count is zero, the read will fail after the initial attempt.
  # read_retry_timeout = "100ms"
  # read_retry_count = 0

  ## Number of consecutive errors before forcing a reconnection
  ## If set to 1 (default), the client will reconnect after a single failed read
  # reconnect_error_threshold = 1

  ## Security policy, one of "None", "Basic128Rsa15", "Basic256",
  ## "Basic256Sha256", or "auto"
  # security_policy = "auto"

  ## Security mode, one of "None", "Sign", "SignAndEncrypt", or "auto"
  # security_mode = "auto"

  ## Path to cert.pem. Required when security mode or policy isn't "None".
  ## If cert path is not supplied, self-signed cert and key will be generated.
  # certificate = "/etc/telegraf/cert.pem"

  ## Path to private key.pem. Required when security mode or policy isn't "None".
  ## If key path is not supplied, self-signed cert and key will be generated.
  # private_key = "/etc/telegraf/key.pem"

  ## Authentication Method, one of "Certificate", "UserName", or "Anonymous".  To
  ## authenticate using a specific ID, select 'Certificate' or 'UserName'
  # auth_method = "Anonymous"

  ## Username and password required for auth_method = "UserName"
  # username = ""
  # password = ""

  ## Option to select the metric timestamp to use. Valid options are:
  ##     "gather" -- uses the time of receiving the data in telegraf
  ##     "server" -- uses the timestamp provided by the server
  ##     "source" -- uses the timestamp provided by the source
  # timestamp = "gather"

  ## Client trace messages
  ## When set to true, and debug mode enabled in the agent settings, the OPCUA
  ## client's messages are included in telegraf logs. These messages are very
  ## noisey, but essential for debugging issues.
  # client_trace = false

  ## Include additional Fields in each metric
  ## Available options are:
  ##   DataType -- OPC-UA Data Type (string)
  # optional_fields = []

  ## Node ID configuration
  ## name              - field name to use in the output
  ## namespace         - OPC UA namespace of the node (integer value 0 thru 3)
  ## identifier_type   - OPC UA ID type (s=string, i=numeric, g=guid, b=opaque)
  ## identifier        - OPC UA ID (tag as shown in opcua browser)
  ## default_tags      - extra tags to be added to the output metric (optional)
  ##
  ## Use either the inline notation or the bracketed notation, not both.

  ## Inline notation (default_tags not supported yet)
  # nodes = [
  #   {name="", namespace="", identifier_type="", identifier=""},
  # ]

  ## Bracketed notation
  # [[inputs.opcua.nodes]]
  #   name = "node1"
  #   namespace = ""
  #   identifier_type = ""
  #   identifier = ""
  #   default_tags = { tag1 = "value1", tag2 = "value2" }
  #
  # [[inputs.opcua.nodes]]
  #   name = "node2"
  #   namespace = ""
  #   identifier_type = ""
  #   identifier = ""

  ## Node Group
  ## Sets defaults so they aren't required in every node.
  ## Default values can be set for:
  ## * Metric name
  ## * OPC UA namespace
  ## * Identifier
  ## * Default tags
  ##
  ## Multiple node groups are allowed
  #[[inputs.opcua.group]]
  ## Group Metric name. Overrides the top level name.  If unset, the
  ## top level name is used.
  # name =

  ## Group default namespace. If a node in the group doesn't set its
  ## namespace, this is used.
  # namespace =

  ## Group default identifier type. If a node in the group doesn't set its
  ## namespace, this is used.
  # identifier_type =

  ## Default tags that are applied to every node in this group. Can be
  ## overwritten in a node by setting a different value for the tag name.
  ##   example: default_tags = { tag1 = "value1" }
  # default_tags = {}

  ## Node ID Configuration. Array of nodes with the same settings as above.
  ## Use either the inline notation or the bracketed notation, not both.

  ## Inline notation (default_tags not supported yet)
  # nodes = [
  #  {name="node1", namespace="", identifier_type="", identifier=""},
  #  {name="node2", namespace="", identifier_type="", identifier=""},
  #]

  ## Bracketed notation
  # [[inputs.opcua.group.nodes]]
  #   name = "node1"
  #   namespace = ""
  #   identifier_type = ""
  #   identifier = ""
  #   default_tags = { tag1 = "override1", tag2 = "value2" }
  #
  # [[inputs.opcua.group.nodes]]
  #   name = "node2"
  #   namespace = ""
  #   identifier_type = ""
  #   identifier = ""

  ## Enable workarounds required by some devices to work correctly
  # [inputs.opcua.workarounds]
  #   ## Set additional valid status codes, StatusOK (0x0) is always considered valid
  #   # additional_valid_status_codes = ["0xC0"]

  # [inputs.opcua.request_workarounds]
  #   ## Use unregistered reads instead of registered reads
  #   # use_unregistered_reads = false
```

## Node Configuration

An OPC UA node ID may resemble: "ns=3;s=Temperature". In this example:

- ns=3 is indicating the `namespace` is 3
- s=Temperature is indicting that the `identifier_type` is a string and
  `identifier` value is 'Temperature'
- This example temperature node has a value of 79.0

To gather data from this node enter the following line into the 'nodes'
property above:

```text
{field_name="temp", namespace="3", identifier_type="s", identifier="Temperature"},
```

This node configuration produces a metric like this:

```text
opcua,id=ns\=3;s\=Temperature temp=79.0,Quality="OK (0x0)" 1597820490000000000
```

With 'DataType' entered in Additional Metrics, this node configuration
produces a metric like this:

```text
opcua,id=ns\=3;s\=Temperature temp=79.0,Quality="OK (0x0)",DataType="Float" 1597820490000000000
```

If the value is an array, each element is unpacked into a field
using indexed keys. For example:

```text
opcua,id=ns\=3;s\=Temperature temp[0]=79.0,temp[1]=38.9,Quality="OK (0x0)",DataType="Float" 1597820490000000000
```

## Group Configuration

Groups can set default values for the namespace, identifier type, and
tags settings.  The default values apply to all the nodes in the
group.  If a default is set, a node may omit the setting altogether.
This simplifies node configuration, especially when many nodes share
the same namespace or identifier type.

The output metric will include tags set in the group and the node.  If
a tag with the same name is set in both places, the tag value from the
node is used.

This example group configuration has three groups with two nodes each:

```toml
  # Group 1
  [[inputs.opcua.group]]
    name = "group1_metric_name"
    namespace = "3"
    identifier_type = "i"
    default_tags = { group1_tag = "val1" }
    [[inputs.opcua.group.nodes]]
      name = "name"
      identifier = "1001"
      default_tags = { node1_tag = "val2" }
    [[inputs.opcua.group.nodes]]
      name = "name"
      identifier = "1002"
      default_tags = {node1_tag = "val3"}

  # Group 2
  [[inputs.opcua.group]]
    name = "group2_metric_name"
    namespace = "3"
    identifier_type = "i"
    default_tags = { group2_tag = "val3" }
    [[inputs.opcua.group.nodes]]
      name = "saw"
      identifier = "1003"
      default_tags = { node2_tag = "val4" }
    [[inputs.opcua.group.nodes]]
      name = "sin"
      identifier = "1004"

  # Group 3
  [[inputs.opcua.group]]
    name = "group3_metric_name"
    namespace = "3"
    identifier_type = "i"
    default_tags = { group3_tag = "val5" }
    nodes = [
      {name="name", identifier="1001"},
      {name="name", identifier="1002"},
    ]
```

## Connection Service

This plugin actively reads to retrieve data from the OPC server.
This is done every `interval`.

## Metrics

The metrics collected by this input plugin will depend on the
configured `nodes` and `group`.

## Example Output

```text
group1_metric_name,group1_tag=val1,id=ns\=3;i\=1001,node1_tag=val2 name=0,Quality="OK (0x0)" 1606893246000000000
group1_metric_name,group1_tag=val1,id=ns\=3;i\=1002,node1_tag=val3 name=-1.389117,Quality="OK (0x0)" 1606893246000000000
group2_metric_name,group2_tag=val3,id=ns\=3;i\=1003,node2_tag=val4 Quality="OK (0x0)",saw=-1.6 1606893246000000000
group2_metric_name,group2_tag=val3,id=ns\=3;i\=1004 sin=1.902113,Quality="OK (0x0)" 1606893246000000000
```
