TCP client

Create a TCP client channel with the runtime, the channel configuration, the endpoints to connect to, and a ClientStateListener.

Rust

let channel = spawn_master_tcp_client(
    LinkErrorMode::Close,
    get_master_channel_config(master_address)?,
    EndpointList::new(endpoint.to_string(), &[]),
    ConnectStrategy::default(),
    LogListener::create("client"),
);

note

The function is called within the context of the Tokio runtime, and is therefore implicit in Rust.

C

dnp3_master_channel_t *channel = NULL;
dnp3_endpoint_list_t *endpoints = dnp3_endpoint_list_create(endpoint);
dnp3_param_error_t err = dnp3_master_channel_create_tcp(
    runtime,
    DNP3_LINK_ERROR_MODE_CLOSE,
    get_master_channel_config(),
    endpoints,
    dnp3_connect_strategy_init(),
    get_client_state_listener(),
    &channel
);
dnp3_endpoint_list_destroy(endpoints);
// check error

C++

dnp3::EndpointList endpoints(endpoint);

auto channel = dnp3::MasterChannel::create_tcp_channel(
    runtime,
    dnp3::LinkErrorMode::close,
    get_master_channel_config(),
    endpoints,
    dnp3::ConnectStrategy(),
    create_client_state_listener()
);

Java

MasterChannel channel =
        MasterChannel.createTcpChannel(
                runtime,
                LinkErrorMode.CLOSE,
                getMasterChannelConfig(),
                new EndpointList(endpoint),
                new ConnectStrategy(),
                state -> System.out.println("client state: " + state));

C#

var channel = MasterChannel.CreateTcpChannel(
    runtime,
    LinkErrorMode.Close,
    GetMasterChannelConfig(),
    new EndpointList(endpoint),
    new ConnectStrategy(),
    new LogListener("client")
);

EndpointList

An EndpointList contains remote endpoints the master will try to connect to. It must have at least one entry; additional entries serve as backups. The channel tries each endpoint in order, back to back, until one connects. After a successful connection, the next attempt starts again at the first endpoint. Each endpoint is a <host>:<port> tuple where "host" is:

• IPv4 address
• IPv6 address
• Domain name

ConnectStrategy

The ConnectStrategy controls the rate at which the master retries failed connection attempts. The master uses exponential backoff when attempting to establish a connection. Each time every endpoint in the list fails, the master waits before trying the list again. This delay doubles from minConnectDelay up to maxConnectDelay. If a connection fails after previously connecting, it will wait reconnectDelay before the next attempt.