Copyright 2019 ID TECH. All rights reserved.
Document Number: 80145503-001
Page 21 of 32
8.4.
USB KB Communication Command and Response Format
The Augusta supports USB-KB communication (only) while in “Legacy Mode.”
Legacy Mode is compatible with ID TECH’s “SecureMag” magstripe-only card reader.
Please see ID TECH manual P/N 80096504-001, the SecureMag Encrypted MagStripe Reader User
Manual, for additional information regarding the SecureMag (Legacy Mode) protocol and command set.
Note that USB-KB commands use ID Tech's ITP protocol, in which commands are wrapped with STX
(0x02) and ETX (0x03), followed by an LRC value that represents the XOR of all preceding byte values.
(No checksum is used.) For example:
Command: 52 22 (Get Firmware Version)
This command would be sent as (hex) 02 52 22 03 71, where 0x71 is the LRC value.
USB HID Communication Command and Response Format
In EMV Hybrid Mode, Augusta uses ID TECH proprietary NGA protocol format commands and responses
in USB communications. The NGA protocol exchanges data using the following format:
<0x02> <Len_Low><Len_High> <Command Body/Response
Body/Notification Body> <LRC> <CheckSUM> <0x03>
Where:
•
<0x02>
is STX (Start of Text)
•
<Len_Low><Len_High>
is the length of the
<Command Body/Response
Body/Notification Body>
in hexadecimal byte values.
•
<LRC>
is LRC (exclusive OR) of
<Command Body/Response Body/Notification
Body>
byte values. (XOR all bytes together. The result is the LRC.)
•
<CheckSUM>
is SUM of
<Command Body/Response Body/Notification Body>
values, disregarding overflow. (Add all bytes; the result, mod-256, is the checksum.)
•
<0x03>
is ETX (End of Text)
•
Response Body is
[<Response Status> + <Response Data>]
<Response Status>
: 1 byte.
<Response Data>
: n bytes.
If
<Response Status>
is ACK, Several bytes needed.
If
<Response Status>
is NAK, Response data is Error code (2 bytes), or Error code
(2 bytes) + Tag (1 or 2 bytes; this is for ICC L2 response).
•
Command Body is
[<Command> + <Command Parameters>]
•
Notification Body is
[ xxxxxxxxxxxxxxxxxxxx ]