ACS ACR38 SAM Smart Card Reader - Manual (Page 11)

ACR38x – Reference Manual [email protected]
Version 6.02 www.acs.com.hk
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00h = command successfully executed
Otherwise = error in command data, or command cannot be executed
A table listing the possible values of the status byte and the
corresponding meaning is given in Appendix B.
Data Length Number of subsequent data bytes, and is encoded in 2 bytes. The first
byte (MSB) and second byte (LSB) represent data length N.
Data Data contents of the command.
For a READ_DATA command, for example, the data bytes would contain
the contents of the memory addresses read from the card. The data
bytes can represent values read from the card and/or status information.
Note: Responses are sent from ACR38x to the host computer through BULK IN endpoint.
7.3. Card Status Message
When a card is being inserted into the ACR38x or an inserted card is being removed from the
ACR38x while the ACR38x is in idle mode, i.e. not executing a command, the ACR38x transmits a
Card Status Message to notify the host computer of the change in the card insertion status.
The Card Status Message consists of the following structure and contents:
Card Status Message for Card Insertion
Byte 1 2 3 4
Header Status Data Length
01h C1h 00h 00h
Card Status Message for Card Removal
Byte 1 2 3 4
Header Status Data Length
01h C0h 00h 00h
A Card Status Message is transmitted only once for every card insertion or removal. The ACR38x
does not expect an acknowledgement signal from the computer. After transmitting a status message,
the ACR38x waits for the next command from the computer.
Note: Card Status Messages are sent from ACR38x to the host computer through INTERRUPT IN
endpoint.