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Hi pvbrowser community,

I've found an issue in a recent project, about using several instances of modbus_client with several slaves .ini files.

What I want is to communicate with several slaves via modbus TCP/IP, for achieving this, I'm running several instances of modbus_client chosing differents .ini files.

The issue I'm seeing is that there is some kind of competition between the instances, making communications very irregular. The first modbus_client seems to be quicker, and the last one the slower, and sometimes communications freezes during minutes, no refreshing any tag from the slave station.

It could be interesting to implement a sequential communication inside a single modbus_client instance with all stations, as in modbus RTU?

Someone else has already faced this problem?
Thanks!

That is,

I increase the SHARED_MEMORY_SIZE further than the default "65536" and I get a segmentation fault.

cheers

Hi,

I've found a bug when using the modbus_client example for reading data from a M340 PLC.

it's TCP/IP communications with 20 cycles of 50 holdingRegisters each. All from the same slave.

When I have an error in communications I read data delayed 1 cycle before (1 cycle every cycle error), I've tested it finally by connecting and removing the RJ45 plug.

I've bypassed it by reseting the rlsocket construction when a modbus->response is not OK (in the modbusCycle function)

      ret = modbus->response( &slave, &function, localData);
      if(ret < 0)
	{
	  int cnt = provider->readErrorCount() + 1;
	  if(cnt >= 256*256) cnt = 0;
	  provider->setReadErrorCount(cnt);
	  poll_slave_counter[slave] = n_poll_slave;
	  //ADDED
	  printf("RESETTING MODBUS! \n");
	  delete modbus;
	  modbus = new rlModbus(1024,protocol);
	  delete mysocket;
	  mysocket = new rlSocket(ip,port,1);
	  modbus->registerSocket(mysocket);
	  mysocket->connect();
	  ////
	}

I've seen the code at low level but I don't know the reason.
Thanks!

pd:using last version form github, GNU/Linux ubuntu 16.04 64 bits.