The IOCTL_SMARTCARD_POWER DeviceIoControl operation consists of three minor IOCTL codes. This code can be:
| Code | Meaning | 
|---|---|
| SCARD_COLD_RESET | Power down the card and power it up again. | 
| SCARD_WARM_RESET | Perform a warm reset of the card. | 
| SCARD_POWER_DOWN | Switch off the card power. | 
Information is set to the length of the ATR returned by the card. Status is set to:
| Status | Meaning | 
|---|---|
| STATUS_SUCCESS | Successful operation. | 
| STATUS_UNRECOGNIZED_MEDIA | Unknown or unsupported card inserted. | 
| STATUS_NO_MEDIA | No card in reader. | 
| STATUS_IO_TIMEOUT | The operation has timed out. | 
The IOCTL_SMARTCARD_POWER DeviceIoControl operation consists of three minor IOCTL codes. This code can be:
| Code | Meaning | 
|---|---|
| SCARD_COLD_RESET | Power down the card and power it up again. | 
| SCARD_WARM_RESET | Perform a warm reset of the card. | 
| SCARD_POWER_DOWN | Switch off the card power. | 
Following are possible return values.
| Value | Meaning | 
|---|---|
| STATUS_SUCCESS | Successful operation. | 
| STATUS_UNRECOGNIZED_MEDIA | Unknown or unsupported card inserted. | 
| STATUS_NO_MEDIA | No card in reader. | 
| STATUS_IO_TIMEOUT | The operation has timed out. |