The TCommLSWrite structure

 // CommLSWrite
 TCommLSWrite   struct
  Result                sbyte   // The function call result.
  Port          byte    // The port to which the I2C device is connected.
  Buffer                byte[]  // The buffer containing data to be written to the I2C device.
  ReturnLen     byte    // The number of bytes that you want to read from the I2C device after writing the data.  If no read is planned set this to zero.
 TCommLSWrite   ends

Possible Result values include ERR_COMM_CHAN_INVALID, ERR_COMM_CHAN_NOT_READY, ERR_INVALID_SIZE, and NO_ERR.