U2C_RESULT U2C_PutAck(
      HANDLE hDevice,
      BOOL bAck
);
The U2C_PutAck() function generates acknowledge or not-acknowledge condition according to the value passed in bAck parameter. This function does not finish the I2C bus transaction after transmission, so at the end of I2C transaction U2C_Stop() function has to be called.
Parameters:
- hDevice
- Handle to the U2C-12 device. 
- bAck
- This parameter determines whether acknowledge or non-acknowledge should be generated. If bAck is TRUE - acknowledge will be generated, if bAck is FALSE - non-acknowledge will be generated. 
Return values:
U2C_SUCCESS
Acknowledge / non-acknowledge condition was successfully generated.
U2C_HARDWARE_NOT_FOUND
U2C-12 device referenced by hDevice handle was not found.