[Bug]: 0.13.0-SNAPSHOT S7 closes TCP connection

[agrazio]

What happened?

Reading eight tags every second from a S7_1200 PLC with S7 with version 0.12.0 it works, but with 0.13.0-SNAPSHOT after a while the connection drops and cannot be restored; it gets stuck in a loop at:

[plc4x-s7ha-thread-1] INFO org.apache.plc4x.java.s7.readwrite.protocol.S7HPlcConnection - Creating primary connection. [plc4x-s7ha-thread-1] INFO org.apache.plc4x.java.transport.tcp.TcpChannelFactory - Configuring Bootstrap with org.apache.plc4x.java.s7.readwrite.configuration.S7TcpTransportConfiguration@5f4b0cf4 [plc4x-s7ha-thread-1] INFO org.apache.plc4x.java.s7.readwrite.protocol.S7HPlcConnection - Reconnecting primary channel. [nioEventLoopGroup-427-1] INFO org.apache.plc4x.java.s7.readwrite.protocol.S7HMuxImpl - Unregistered of channel: PRIMARY [nioEventLoopGroup-427-1] INFO org.apache.plc4x.java.s7.readwrite.protocol.S7HMuxImpl - io.netty.channel.embedded.EmbeddedEventLoop@7da0be76 [plc4x-s7ha-thread-1] INFO org.apache.plc4x.java.s7.readwrite.protocol.S7HPlcConnection - Creating primary connection. [plc4x-s7ha-thread-1] INFO org.apache.plc4x.java.transport.tcp.TcpChannelFactory - Configuring Bootstrap with org.apache.plc4x.java.s7.readwrite.configuration.S7TcpTransportConfiguration@5f4b0cf4 [plc4x-s7ha-thread-1] INFO org.apache.plc4x.java.s7.readwrite.protocol.S7HPlcConnection - Reconnecting primary channel. [nioEventLoopGroup-428-1] INFO org.apache.plc4x.java.s7.readwrite.protocol.S7HMuxImpl - Unregistered of channel: PRIMARY [nioEventLoopGroup-428-1] INFO org.apache.plc4x.java.s7.readwrite.protocol.S7HMuxImpl - io.netty.channel.embedded.EmbeddedEventLoop@7da0be76

Example code:

public static void main(String[] args) {
        initialize();
        scheduler.scheduleAtFixedRate(() -> executeRead(config.getTags()), 0, 1000, TimeUnit.MILLISECONDS);
}

public static void initialize() {
    cachedPlcConnectionManager = CachedPlcConnectionManager.getBuilder().build();
    config = Configuration.getConfiguration();
    scheduler.scheduleAtFixedRate(() -> executeRead(config.getTags()), 0, 10, TimeUnit.MILLISECONDS);
}

public static void executeRead(List<Configuration.Tag> tags) {
    try (PlcConnection plcConnection = cachedPlcConnectionManager.getConnection(config.getDeviceAddress())) {
        if (!plcConnection.getMetadata().isReadSupported()) {
            System.out.printf("[%s] Connection does not support reading%n", LocalDateTime.now());
            return;
        }

        PlcReadRequest.Builder readRequestBuilder = plcConnection.readRequestBuilder();
        for (Configuration.Tag tag : tags) {
            readRequestBuilder.addTagAddress(tag.getName(), tag.getAddress());
        }

        PlcReadRequest readRequest = readRequestBuilder.build();
        PlcReadResponse response = readRequest.execute().get();
        processResponse(response);

    } catch (PlcConnectionException e) {
        System.out.printf("[%s] Connection error: %s%n", LocalDateTime.now(), e.getMessage());
    } catch (Exception e) {
        System.out.printf("[%s] Error during PLC read: %s%n", LocalDateTime.now(), e.getMessage());
    }
}

On failure, it creates up to 40 connections, then closes them, and continues opening and closing connections without establishing a working one.

Version

v0.13.0-SNAPSHOT

Programming Languages

• plc4j
• plc4go
• plc4c
• plc4net

Protocols

• AB-Ethernet
• ADS /AMS
• BACnet/IP
• CANopen
• DeltaV
• DF1
• EtherNet/IP
• Firmata
• KNXnet/IP
• Modbus
• OPC-UA
• S7