Get encryption counter command – MagTek MagneSafe V5 User Manual

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MagneSafe V5

72

Example Response Read Oldest Transaction (Hex):

Result Code Data Len

Data

00

00


Erase Oldest Transaction Command (Flash Reader Only)

Command number:

0x18

Description:

This command is used to erase the oldest transaction (card swipe) stored in
the reader. It has no request and no response data. The response indicates
whether or not a transaction was erased. If there are no stored
transactions, the request will fail indicating no stored transactions. If there
is a stored transaction but it has not been read (using the Read Oldest
Transaction
command) since the most recent power up, the request will
fail indicating the transaction must be read before it can be removed.


Data structure:

Request Data: None
Response Data: None


Result codes:

0x00 (Success, a transaction was erased)
0x01 (Failure, no transactions to erase)
0x07 (Sequence error, transaction must be retrieved before erasure)


Example Request Erase Oldest Transaction (Hex):

Cmd Num

Data Len

Data

18

00


Example Response Erase Oldest Transaction (Hex):

Result Code Data Len

Data

00

00


Get Encryption Counter Command

Command number:

0x1C

Description:

This command is used to Get the Encryption Counter. The Encryption
Counter gives the maximum number of transactions that can be performed
by the reader. A transaction is either an encrypted card swipe or a
correctly completed Activation Sequence (Activate Authenticated Mode
followed by correct Activation Challenge Reply).


The Encryption Counter has three possible states:

1. Disabled – value 0xFFFFFF – In this state there is no limit to the number of

transactions that can be performed.

2. Expired – value 0x000000 – This state indicates that all transactions are prohibited
3. Active – value 1 to 1,000,000 (0x000001 to 0x0F4240) – In this state, each

transaction causes the Encryption Counter to be decremented and allows transactions
to be processed. If an Activation Sequence decrements the Encryption Counter to 0, a
last encrypted card swipe will be permitted.

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