Mif command group
With this command group, you can access MIFARE cards in low-level mode.
Whenever a card enters the HF field, it will be in idle state. From the idle state, a card switches to the requested state as soon as the Mif.Request command is executed. Cards in requested state participate in the anti-collision sequence, controlled by the Mif.Anticoll command, resulting in an unambiguous serial number belonging to one of the cards in the HF field. The card with this serial number may now be selected with the Mif.Select command. All other cards will fall back to idle state again and wait for the next call of the Mif.Request command. The selected card, however, changes from requested state to selected state.
The Mif.Anticoll and Mif.Select commands can only process serial numbers with a length of 4 bytes. Since 2010, however, MIFARE cards with a 7-byte serial number are available. Please use the ISO 14443-3 (Type A) command group to select and process cards with 7-byte serial numbers.
When a card is in selected state, communication with the card is possible. Nevertheless, it is necessary to be authenticated before a sector of the card can be accessed. Authentication can be performed either with the Mif.AuthE2 command or with the Mif.AuthUser command. Both commands send a key to the currently selected card along with information regarding whether this key should be compared to key A or key B on the card. If the given key matches the corresponding sector's key (either key A or key B, as specified in the command's parameters), then access according to the access conditions of the desired sector will be granted.
Finally, a card that is in select state can be set to halt state. A card in halt state will not respond to any command unless a specially parameterized Mif.Request command is called, or when it leaves and then re-enters the HF field of the reader's antenna. The halt state is helpful when it is necessary to deal with multiple cards present in the reader's antenna HF field.
The Mif.Read and Mif.Write commands can be use to read/write data from/to a certain block. Additionally, a data sector may be turned into a special value sector (also called value block ), which is initialized with a specific starting value and can then only be changed by means of increment and decrement operations using the ChangeValue or ChangeValueBackup commands. Value sectors are very useful in some scenarios, such as for cash-based applications. To create a value sector, it is simply required to write specially formatted data to it:
- The first 4 bytes (bytes 0-3) represent the initially stored value.
- The following 4 bytes (bytes 4-7) have to be the two's complement of the first 4 bytes.
- The next 4 bytes (bytes 8-11) are a copy of the first 4 bytes.
- The last 4 bytes (bytes 12-15) contain the 1-byte address of a block which can be used for backup management. This address is stored on both byte 12 and byte 14, while its two's complement is stored on both byte 13 and byte 15. These 4 bytes are not affected by calls of the Mif.ChangeValue and Mif.ChangeValueBackup commands.
Each increment and decrement operation has to be followed by a transfer operation, using the Mif.TransferBlock command, in order to make the increment/decrement persistent. This feature guarantees that no data will be lost during a recalculation of the value on the card.
WARNING: This command set is not available in all Baltech reader firmware variants.
|BRP status||BRP Library Error Code||Mnemonic||Description|
|0x01||0x1001 (4097)||Mif.ErrNoTag||There's no card in the HF field, or the card doesn't respond.|
|0x02||0x1002 (4098)||Mif.ErrCrc||The response frame is invalid, e.g. it may contain an invalid CRC checksum. Please rerun the command.|
|0x04||0x1004 (4100)||Mif.ErrAuth||Card authentication has failed.|
|0x05||0x1005 (4101)||Mif.ErrParity||Legacy error code: The parity bits don't match the transmitted data. Authentication has been lost. Please reauthenticate and rerun the commands.|
|0x06||0x1006 (4102)||Mif.ErrCode||The card behaves in an unspecified way. Please rerun the command or reselect the card.|
|0x08||0x1008 (4104)||Mif.ErrSnr||Legacy error code: The serial number is wrong.|
|0x09||0x1009 (4105)||Mif.ErrKey||The key in the SAM/crypto memory is invalid or missing.|
|0x0A||0x100A (4106)||Mif.ErrNotauth||Card authentication has failed. The current configuration/state doesn't allow the requested command.|
|0x0B||0x100B (4107)||Mif.ErrBitcount||Legacy error code: HF data transition error. The number of received bits is invalid.|
|0x0C||0x100C (4108)||Mif.ErrBytecount||Legacy error code: HF data transition error. The number of received bytes is invalid.|
|0x0E||0x100E (4110)||Mif.VcsAndProxCheckError||The proximity check has timed out. Please reselect the card.|
|0x0F||0x100F (4111)||Mif.ErrWrite||Writing to the card has failed. Please rerun the command or check the access conditions.|
|0x10||0x1010 (4112)||Mif.ErrInc||Legacy error code: Increment couldn't be performed.|
|0x11||0x1011 (4113)||Mif.ErrDecr||Legacy error code: Decrement couldn't be performed.|
|0x12||0x1012 (4114)||Mif.ErrRead||Reading data from the card has failed. Please rerun the command or check the access conditions.|
|0x13||0x1013 (4115)||Mif.ErrOvfl||Legacy error code: An overflow occurred during decrement or increment.|
|0x15||0x1015 (4117)||Mif.ErrFraming||The response frame is invalid, e.g. it may contain an invalid number of bits. Please rerun the command.|
The command has been aborted because the HF
interface has been requested by another task or
command. Please reselect the card.
This error only occurs when you combine VHL and low-level commands. We highly recommend you avoid that combination as these 2 command sets will interfere with each other's card states.
|0x17||0x1017 (4119)||Mif.ErrCmd||The specified command or parameters are unknown.|
|0x18||0x1018 (4120)||Mif.ErrColl||An error occurred in the anti-collision sequence. Please reselect the card.|
|0x1A||0x101A (4122)||Mif.ErrReaderChipCommunication||Communication with the reader's HF interface has failed. Please reset the HF interface with Sys.HFReset and check the reader status with Sys.GetBootStatus.|
|0x1D||0x101D (4125)||Mif.ErrFirmwareNotSupported||This command isn't supported by the reader firmware.|
|0x1E||0x101E (4126)||Mif.ErrVal||A value operation, e.g. increment or decrement, has failed. This may have several reasons, e.g. an invalid value format, or the value to manipulate doesn't exist on the card.|
|0x1F||0x101F (4127)||Mif.ErrIntegrity||Secure messaging error: The CRC or MAC checksum doesn't match the transmitted data. Authentication has been lost. Please reauthenticate and rerun the commands, or check the security conditions.|
|0x20||0x1020 (4128)||Mif.CondNotvalid||Card error as per MIFARE specification: Condition of use not satisfied.|
|0x21||0x1021 (4129)||Mif.ErrHwNotSupported||This command isn't supported by the reader hardware, i.e. by the SAM or reader chip.|
|0x22||0x1022 (4130)||Mif.ErrSamUnlock||Unlocking/authenticating with the SAM has failed. Please check the SamAVx configuration values.|
|0x23||0x1023 (4131)||Mif.ErrSamCommunication||Communication with the SAM has failed. This may have several reasons, e.g. the wrong SAM type or a failure to activate the SAM. Please check the SAM status and reset the reader with Sys.Reset.|