feat(plc4j/ab-eth): Enable AB-Ethernet Driver reading

[andvasp]

Hi everybody!

In this PR I am enabling the AB-Ethernet Driver reading. Also implemented the missing multiple tags reading.

About the transaction counter reinitialization, should not be set to 10 like the declaration?

@chrisdutz, Do you remeber why 10? Using one Opc Server it starts with 32. But 10 is working perfectly!

transaction counter reinitialize

  private final AtomicInteger transactionCounterGenerator = new AtomicInteger(10);
...
  if (transactionCounterGenerator.get() == 0xFFFF) {
      transactionCounterGenerator.set(1);
  }

[chrisdutz]

Hehe... That's a relic from the old times in s7... There were several messages exchanged in order to establish the connection, so we simply had the counter start at 10...i guess there's absolutely no reason for this in ab-eth.

[andvasp]

hehe...

What about the transaction counter reinitialization, the reinitialized value should not be the initial value on the variable declaration?

I tested using value 1 on the initialization and it works too. I checked the specification and it does not mention any constraint of the first value.

[chrisdutz]

Feel free to change whatever you need.

[chrisdutz]

Ups ... sorry ... the one button is directly next to the other one :-/