AssociationConfig

AssociationConfig sets how the master works with one outstation. The outstation's address isn't part of it: you pass the address separately when you create the association. The configuration answers these questions:

Decision	Why it matters
What to read at startup	The integrity poll gives you the current value of every point, at startup and after the outstation restarts
Whether the outstation reports unsolicited	Which event classes the master turns off and back on at startup. Choose none for an outstation that doesn't report unsolicited, and poll it instead
Whether and how to synchronize time	Whether the master sets the outstation's clock when it asks for the time, and with which procedure. See Time Synchronization
How to react to the outstation's indications	Which event classes the master scans when the outstation reports events, and whether it runs an integrity poll when the outstation's event buffer overflows
How long to wait, and how to retry	How long the master waits for each response, and how it retries automatic tasks that fail
When to check a quiet link	How long the link can be silent before the master sends a keep-alive, if at all
How many requests can wait	How many of your requests can queue on the association before new ones fail at once

The examples configure an association like this:

Rust

fn get_association_config() -> AssociationConfig {
    let mut config = AssociationConfig::new(
        // disable unsolicited first (Class 1/2/3)
        EventClasses::all(),
        // after the integrity poll, enable unsolicited (Class 1/2/3)
        EventClasses::all(),
        // perform startup integrity poll with Class 1/2/3/0
        Classes::all(),
        // don't automatically scan Class 1/2/3 when the corresponding IIN bit is asserted
        EventClasses::none(),
    );
    config.auto_time_sync = Some(TimeSyncProcedure::Lan);
    config.keep_alive_timeout = Some(Duration::from_secs(60));
    config
}

C

dnp3_association_config_t get_association_config(void)
{
    dnp3_association_config_t config = dnp3_association_config_init(
        // disable unsolicited first (Class 1/2/3)
        dnp3_event_classes_all(),
        // after the integrity poll, enable unsolicited (Class 1/2/3)
        dnp3_event_classes_all(),
        // perform startup integrity poll with Class 1/2/3/0
        dnp3_classes_all(),
        // don't automatically scan Class 1/2/3 when the corresponding IIN bit is asserted
        dnp3_event_classes_none());

    config.auto_time_sync = DNP3_AUTO_TIME_SYNC_LAN;
    config.keep_alive_timeout = 60;
    return config;
}

C++

dnp3::AssociationConfig config(
    // disable unsolicited first (Class 1/2/3)
    dnp3::EventClasses::all(),
    // after the integrity poll, enable unsolicited (Class 1/2/3)
    dnp3::EventClasses::all(),
    // perform startup integrity poll with Class 1/2/3/0
    dnp3::Classes::all(),
    // don't automatically scan Class 1/2/3 when the corresponding IIN bit is asserted
    dnp3::EventClasses::none()
);
config.auto_time_sync = dnp3::AutoTimeSync::lan;
config.keep_alive_timeout = std::chrono::seconds(60);

Java

private static AssociationConfig getAssociationConfig() {
  return new AssociationConfig(
          // disable unsolicited first (Class 1/2/3)
          EventClasses.all(),
          // after the integrity poll, enable unsolicited (Class 1/2/3)
          EventClasses.all(),
          // perform startup integrity poll with Class 1/2/3/0
          Classes.all(),
          // don't automatically scan Class 1/2/3 when the corresponding IIN bit is asserted
          EventClasses.none())
    .withAutoTimeSync(AutoTimeSync.LAN)
    .withKeepAliveTimeout(Duration.ofSeconds(60));
}

C#

private static AssociationConfig GetAssociationConfig()
{
    return new AssociationConfig(
        // disable unsolicited first (Class 1/2/3)
        EventClasses.All(),
        // after the integrity poll, enable unsolicited (Class 1/2/3)
        EventClasses.All(),
        // perform startup integrity poll with Class 1/2/3/0
        Classes.All(),
        // don't automatically scan Class 1/2/3 when the corresponding IIN bit is asserted
        EventClasses.None()
    )
    .WithAutoTimeSync(AutoTimeSync.Lan)
    .WithKeepAliveTimeout(TimeSpan.FromSeconds(60));
}

Initialization

The master turns unsolicited reporting off, reads everything with an integrity poll, then turns unsolicited reporting back on. That way it starts from the current value of every point before changes stream in. If the outstation asks for the time and automatic time synchronization is configured, the master synchronizes it before the integrity poll:

The master skips any step whose classes you leave empty. For an outstation that doesn't support unsolicited reporting, set the classes to disable and to enable at startup to none, and the master performs only the integrity poll.

Scheduling

The master runs these startup tasks, and others such as clearing the restart bit and automatic event scans, alongside your requests and polls. See Automatic Tasks and Scheduling for when each one runs and how a channel orders the work of its associations.