| EBusProtocolException | Communication Error |
| EChecksumException | Checksum error |
| EConnectionWasClosed | Remote peer closed TCP/IP connection |
| EEvaluationExpired | Evaluation expired |
| EFiledesExceeded | File descriptors exceeded |
| EIllegalArgumentError | Illegal argument error |
| EIllegalSlaveAddress | Slave address 0 illegal for serial protocols |
| EIllegalStateError | Illegal state error |
| EInOutError | EInOutError is the VCL base class for file input/output errors |
| EInvalidFrameException | Invalid frame error |
| EInvalidMbapIdException | Invalid MPAB indentifer |
| EInvalidOperation | EInvalidOperation is the VCL base class for invalid operations on a component |
| EInvalidReplyException | Invalid reply error |
| EListenFailed | Listen failed |
| EMbusGatewayPathUnavailableException | Gateway Path Unavailable exception response |
| EMbusGatewayTargetFailureException | Gateway Target Device Failed exception response |
| EMbusIllegalAddressException | Illegal Data Address exception response |
| EMbusIllegalFunctionException | Illegal Function exception response |
| EMbusIllegalValueException | Illegal Data Value exception response |
| EMbusResponseException | Modbus® exception response |
| EMbusSlaveFailureException | Slave Device Failure exception response |
| EOpenErr | Port or socket open error |
| EPortAlreadyBound | TCP port already bound |
| EPortAlreadyOpen | Serial port already open |
| EPortNoAccess | No permission to access serial port or TCP port |
| EPortNotAvail | TCP port not available |
| EReplyTimeoutException | Reply time-out |
| ESendTimeoutException | Send time-out |
| ESocketLibError | Socket library error |
| ETcpipConnectErr | TCP/IP connection error |
| TMbusAsciiMasterProtocol | Modbus ASCII Master Protocol class |
| TMbusMasterFunctions | Base class which implements Modbus data and control functions |
| TMbusRtuMasterProtocol | Modbus RTU Master Protocol class |
| TMbusRtuOverTcpMasterProtocol | Encapsulated Modbus RTU Master Protocol class |
| TMbusSerialMasterProtocol | Base class for serial serial master protocols |
| TMbusTcpMasterProtocol | MODBUS/TCP Master Protocol class |