MagTek USB KB INTELLIHEAD - Manual (Page 19)

Section 4. USB Communications
11
where:
ES = P22 (end sentinel)
LRC = Longitudinal redundancy check character
P5 = Terminating character
P11 = Pre card character
P12 = Post card character
P13 = Pre track character
P14 = Post track character
P18 = Pre card string
P19 = Post card string
Tk1 SS = P20 (ISO/ABA start sentinel)
Tk2 SS = P21 (ISO/ABA 5-bit start sentinel)
P6 (7-bit start sentinel)
Tk3 SS = P8 (ISO/ABA start sentinel)
P9 (AAMVA start sentinel)
P10 (7-bit start sentinel)
All fields with the format P# are programmable configuration property numbers. They are
described in detail later in this document.
PROGRAMMABLE CONFIGURATION OPTIONS
This device has a number of programmable configuration properties. These properties are stored
in non-volatile memory. These properties can be configured at the factory or by the end user
using a program supplied by MagTek. Programming these parameters requires low level
communications with the device. During normal device operation, the device acts like a USB
HID keyboard so the host operating system takes care of all low level communications with the
device so that the application developer is not burdened with these low level details. Details on
how to communicate with the device to change programmable configuration properties follows
in the next few sections. These details are included as a reference only. Most users will not need
to know these details because the device will be configured at the factory or by a program
supplied by MagTek. Most users may want to skip over the next few sections on low level
communications and continue with the details of the configuration properties.
LOW LEVEL COMMUNICATIONS
It is strongly recommended that application software developers become familiar with the HID
specification the USB specification before attempting to communicate directly with this device.
This document assumes that the reader is familiar with these specifications. These specifications
can be downloaded free from
www.usb.org .