The ModbusAsyncRegisterBitWritable component is responsible for sending and reading Boolean values from the device. The component has to be placed under the ModbusAsyncDevice component.

The ModbusAsyncRegusterBitWritable component


The ModbusAsyncRegisterBitWritable component has the following slots:

  • Status: shows the point’s status;
  • Fault Cause: shows the fault cause description;
  • Fault Status: informs about the point error status (true: point read error);
  • Enable: enables or disables the point (true: point enabled, false: point disabled);
  • Address Format: allows to set the register address format (Modbus, decimal);
  • Address: allows to set the register address;
  • Nr Bit: allows to set the bit number in the register;
  • Poll Frequency: allows to set the reading poll frequency (fast, normal, slow);
  • Write Type: allows to set the writing mode (COV: only on the In slot change, COV_PollFequrency: on the In slot change and periodically, PollFequrency: only periodically, COV_LinkSet : only on the In slot change using the "reverse following the link" function);
  • Trigger: allows to trigger the remote enforcement of sending (on rising edge);
  • Out: the current value of reading bit;
  • In: the input slot.


The ModbusAsyncRegisterBitWritable component offers the following actions, available in the context menu:

  • Set True/Set False: writes the value to the In slot and sends it to the device (not active if the In slot has a link connected);
  • Write: sends the value from the In slot to the device;
  • Read: reads the value from the device and sends it to the Out slot;
  • Send Value: sends the value to the device, without changing the value on the In slot.