SM_Close SM_ConfigureSerialConnection SM_ConfigureSerialTimeouts SM_CustomMessage SM_GetAnalogConfig SM_GetAnalogInputConfig SM_GetAnalogInputRanges SM_GetAnalogOutputRanges SM_GetDeviceConfig SM_GetFirmwareVersion SM_GetLastError SM_GetLastFTDIError SM_GetLastWin32Error SM_GetPIODirection SM_GetPIOPresets SM_GlobalCommsReset SM_NotifyInputState SM_NotifyOnInputChange SM_Open SM_OpenSecure SM_ReadAnalogInputs SM_ReadAnalogOutputs SM_ReadDigitalInputs SM_ReadDigitalOutputs SM_ReadPIO SM_SelectDevice SM_SetAnalogConfig SM_SetAnalogInputConfig SM_SetAnalogInputRanges SM_SetCommunications SM_SetPIODirection SM_SetPIOPresets SM_SetPolarity SM_SetSoftwareAddress SM_Version SM_WriteAnalogOutputs SM_WriteDigitalOutputs SM_WritePIO

int __stdcall SM_CustomMessage ( SM_HANDLE  handle, unsigned char *  message, int  messageSize, int  expectedBytes  ) Sends a custom modbus message to the selected device, and retrieves the response. Parameters [in] handle Valid handle returned by SM_Open(). [in] message Message to send beginning with the function code. It will also contain the response on success. [in] messageSize Size in bytes of the outgoing message. Must be less than 1017 bytes. [in] expectedBytes Size in bytes of the expected response. Must be less than 1017 bytes. Return values >=0 Number of bytes successfully read. -1 Invalid SeaMAX handle or connection type or invalid parameter. -2 Modbus: Connection is not established. Check the provided Connection object state. -3 Modbus: Read error waiting for response. Unknown Modbus exception. -7 Modbus CRC was invalid. Possible communications problem. The message parameter should contain the function code and remaining bytes in the message. The header, the Slave ID and the CRC are not required because SeaMAX handles these elements of the message. Note The message parameter must contain an array large enough to hold the return message. See also http://www.modbus.org