[Bug]: [PLC4J] [EtherNet/IP] All values read are null for Allen-Bradley PLC with EtherNet/IP or Logix

[meichf]

What happened?

I wrote two programs according to the documentation on the official website of PLC4X to read Allen Bradley PLC, model Logix5571, but all the values read were null.

Here is the code. The result is that all four tag values in asPlcValue are null.

code for EtherNet/IP protocol:

    String connectionString = "eip://192.168.0.2:44818?slot=0&bigEndian=false";

    try (PlcConnection plcConnection = PlcDriverManager.getDefault().getConnectionManager().getConnection(connectionString)) {
        final PlcReadRequest.Builder readrequest = plcConnection.readRequestBuilder();

    //(3.1)
        readrequest.addTagAddress("tag1", "%A:DINT");
        readrequest.addTagAddress("tag2", "%B:INT");
        readrequest.addTagAddress("tag3", "%C:SINT");
        readrequest.addTagAddress("tag4", "%D:REAL");

        //(3.2)
        final PlcReadRequest rr = readrequest.build();
        //(3.3)
        final PlcReadResponse szlresponse = rr.execute().get();

        PlcValue asPlcValue = szlresponse.getAsPlcValue();

    } catch (PlcConnectionException e) {
        throw new RuntimeException(e);
    } catch (Exception e) {
        throw new RuntimeException(e);
    }
  

code for Logix protocol:

   String connectionString = "logix://192.168.0.2:44818?slot=0&bigEndian=false";

    try (PlcConnection plcConnection = PlcDriverManager.getDefault().getConnectionManager().getConnection(connectionString)) {
        PlcConnectionMetadata metadata = plcConnection.getMetadata();
        final PlcReadRequest.Builder readrequest = plcConnection.readRequestBuilder();

        //(3.1)
        readrequest.addTagAddress("tag1", "A:DINT");
        readrequest.addTagAddress("tag2", "B:INT");
        readrequest.addTagAddress("tag3", "C:SINT");
        readrequest.addTagAddress("tag4", "D:REAL");

        //(3.2)
        final PlcReadRequest rr = readrequest.build();
        //(3.3)
        final PlcReadResponse szlresponse = rr.execute().get();
        //(3.4)
        PlcValue asPlcValue = szlresponse.getAsPlcValue();
        log.info("Tags: " + asPlcValue);
    } catch (PlcConnectionException e) {
        throw new RuntimeException(e);
    } catch (Exception e) {
        throw new RuntimeException(e);
    }`

here is the tags:

Version

v0.12.0

Programming Languages

• [X] plc4j
• [ ] plc4go
• [ ] plc4c
• [ ] plc4net

Protocols

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