User guide

ACR38x – Reference Manual [e-mail]
Version 6.02
www.acs.com.hk
Page 14 of 40
9.0. Commands
9.1. Control Commands
The Control Commands are in charge of the internal operation of the ACR38x. They do not directly
affect the card inserted in the ACR38x and are therefore independent of the selected card type.
9.1.1. GET_ATR_STAT
This command returns relevant information about the particular ACR38x model and the current
operating status such as the firmware revision number, the maximum data length of a command and
response, the supported card types, and whether a card is inserted and powered up or not.
Command Format
Header Instruction Data length
01h 01h 00h 00h
Response Data Format
Header Status
Data length
INTERNAL MAX_C MAX_R C_TYPE C_SEL C_STAT
LEN
01h
Where:
INTERNAL 10 bytes data for internal use only.
MAX_C The maximum number of command data bytes.
MAX_R The maximum number of data bytes that can be requested to be transmitted in a
response.
C_TYPE The card types supported by the ACR38x. This data field is a bitmap with each bit
representing a particular card type. A bit set to '1' means the corresponding card type
is supported by the reader and can be selected with the SELECT_CARD_TYPE
command. The bit assignment is as follows:
Byte
1 2
card type 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
See Appendix A for the correspondence between these bits and the respective card
types.
C_SEL The currently selected card type as specified in a previous SELECT_CARD_TYPE
command. A value of 00h means that no card type has been selected.
C_STAT Indicates whether a card is physically inserted in the reader and whether the card is
powered up:
00h: No card inserted
01h: Card inserted, not powered up
03h: Card powered up