Configuration

Configuration can be done via JSON file, the default file name is proxy_config.json. All the config keys that are not recognized will be ignored, if no configuration is provided for a parameter its default value will be loaded. An example of configuration file can be the following:

{
    "opcServerURL":"opc.tcp://localhost:4840/freeopcua/server/",

    "loggerConfig" :{
        "loglevel" :"info"
    },

    "nodesLoader" : {
        "targetIdentifier" : "browseName",
        "whiteList":["MyVariable"]
    },
    "gRPC" :{
            "port" : 5051
    }
}

OPC related Configs

These configs are related to core features and define how the opc client must behave. They must be placed at the root level of the json file.

Config Key	type	Default	Notes
opcServerURL	string	none	OPC server TCP URL endpoint
reconnectPeriod	int	10 [s]	Time interval [seconds] to wait before retry to reconnect to OPC server
publishingInterval	int	1000 [ms]	This is a subscription parameter, time intervall [millisecond] at which the OPC server will send node values updates.
opcSystemName	string	OPC	Name of the OPC system that will be used for identification

Nodes Loader

These are config related to nodes loading methods and selection rules.

Note

If no selection rules are defined then ALL nodes of type Variable are loaded automatically. If more selection rules are defined they Add/Excludes nodes (of type Variable) based on the following priority order: whiteList, blackList, notContain, contains, matchRegEx.

Config Key	type	Default	Notes
browseNodes	bool	true	If true load nodes via recursively drilling trough the server tree, it may use many network requests. If false will load nodes from an xml file, according to the Nodeset2 OPC specification.
targetIdentifier	string	DisplayName	Node attribute that undergoes selection rules, it can be: displayname, browsename, nodeid. In case of nodeid is necessary to specify also the prefix like i=123 or s=VarName. It is case insensitive.
filename	string	nodeset.xml	Path to the xml file where the nodes are defined. Necessary if browseNodes = false.
whiteList	string[ ]	empty	Accept all nodes with targetIdentifier exactly equal to one of the string in the list. Runs first.
blackList	string[ ]	empty	Exclude nodes with targetIdentifier exactly equal to one of the string in the list. Runs second.
notContain	string[ ]	empty	Excludes nodes with targetIdentifier containing one of the string in the list. Runs before contains and matchRegEx.
contains	string[ ]	empty	Accept nodes with targetIdentifier containing one of the string in the list. Runs before matchRegEx.
matchRegEx	string[ ]	empty	Accept nodes with targetIdentifier matching one of the regular expression string in the list. Runs last.

gRPC-Connector Configs

These configs are related to the gRPC Connector, they must be placed under the key gRPC as follows:

{
    // Other config here

    "gRPC" :{
            "port" : 5051
    }
}

Config Key	type	Default	Notes
host	string	localhost	host name on the network.
port	int	5051	Port on which to listen for client requests

Kafka-Connector Configs

These configs are related to the Kafka-Connector, they must be placed under the keys kafkaProducer and kafkaRPC, there are also two root level configs: KafkaSchemaRegistryURL and KafkaServers, as in the example:

{
    // Other config here

    opcSystemName : "OPC",
    KafkaSchemaRegistryURL : "localhost:8081",
    KafkaServers : "localhost:9092",

    kafkaProducer : {
        // Producer conf
    },
    kafkaRPC : {
        // RPC conf
    }
}

Root level cofigs:

Config Key	type	Default	Notes
opcSystemName	string	OPC	System name is a core variable, it will be used to evaluate the topic names for nodes publishing, see Kafka-Connector
KafkaSchemaRegistryURL	string	localhost:8081	Endpoint of the schema registry
KafkaServers	string	localhost:9092	Comma separated list of kafka brokers. These will be set for the producer and the consumer of the OPC-Proxy, this can be overidden, see below.

kafkaProducer:

Config Key	type	Default	Notes
BootstrapServers	string	localhost:9092	Comma separated list of Kafka brokers endpoints. If not set, this will be set to the value of KafkaServers.
BatchNumMessages	int	10000	See Confluent producer docs
LingerMs	int	100 [ms]	See Confluent producer docs
QueueBufferingMaxKbytes	int	1048576 [Kbytes]	See Confluent producer docs
QueueBufferingMaxMessages	int	100000	See Confluent producer docs
MessageTimeoutMs	int	300000	See Confluent producer docs
EnableIdempotence	bool	false	See Confluent producer docs
RetryBackoffMs	int	100 [ms]	See Confluent producer docs
MessageSendMaxRetries	int	2	See Confluent producer docs

kafkaRPC:

All the non reported kafka consumer configurations are set to default values.

Config Key	type	Default	Notes
BootstrapServers	string	localhost:9092	Comma separated list of Kafka brokers endpoints. If not set, this will be set to the value of KafkaServers.
GroupId	string	OPC	Group ID of the RPC kafka consumer. No other consumer can have this group ID in the whole system. If not set, default is to be set to opcSystemName.
enableKafkaRPC	bool	true	Enable the RPC-style comunication trough kafka topics.
EnableAutoCommit	bool	true	See Confluent consumer docs
EnableAutoOffsetStore	bool	true	See Confluent consumer docs
AutoCommitIntervalMs	int	5000 [ms]	See Confluent consumer docs
SessionTimeoutMs	int	10000 [ms]	See Confluent consumer docs
AutoOffsetReset	string	latest	See Confluent consumer docs
EnablePartitionEof	bool	false	See Confluent consumer docs
FetchWaitMaxMs	int	1000 [ms]	See Confluent consumer docs
FetchMinBytes	int	1	See Confluent consumer docs
HeartbeatIntervalMs	int	3000 [ms]	See Confluent consumer docs

InfluxDB-Connector Configs