Copyright © 2010-2020, International Technologies & Systems Corporation. All rights reserved.
Page 40 of 76
User Manual, SecureHead USB and UART Interface
The KSN is incremented every time the authenticated mode is exited by timeout or card swipe
action. When the authenticated mode is exited by Deactivate Authenticated Mode command, the
KSN will increment when the increment flag is set to 01h.
Command Structure
Host -> Device:
<STX><S><81h><08h for TDES or 10h for AES><Deactivation Data><ETX><CheckSum>
Device -> Host:
<ACK> (success)
<NAK> (fail)
<Deactivation data>: 8-bytes response to Challenge 2. It contains 7 bytes of Challenge 2 with 1
byte of Increment Flag, encrypted by the specified variant of current DUKPT Key
Get Reader Status Command
Command Structure
Host -> Device:
<STX><R><83h><ETX><CheckSum>
Device -> Host:
<ACK><STX><83h><02h><Current Reader Status><Pre-conditon><ETX><CheckSum>
(success)
<NAK> (fail)
Current Reader Status: 2-bytes data with one byte of <Reader State> and one byte of <Pre-
Condition>
Reader State: indicates the current state of the reader
00h: The reader is waiting for Activate Authentication Mode Command. The command must be
sent before the card can be read.
01h: The authentication request has been sent, the reader is waiting for the Activation
Challenge Reply Command.
02h: The reader is waiting for a card swipe.
Pre-condition: specifies how the reader goes to its current state as follows
00h: The reader has no card swipes and has not been authenticated since it was powered up.
01h: Authentication Mode was activated successfully. The reader processed a valid Activation
Challenge Reply command.