USB Interfaces User’s Guide
1 - 11
HID POS Interface
Note: HID POS does not require a custom driver installation. However, a HID interface on Windows 98 does. See page 1-2 for
further information.
The HID POS interface is recommended for new applications. It can send up to 56 characters in a single USB report and is much
faster than keyboard emulation. It conforms to the USB standard documents "Device Class Definition for Human Interface
Devices (HID)" V1.11 (
http://www.usb.org/developers/devclass_docs/HID1_11.pdf
), and "HID Point of Sales Usage Tables"
V1.02 (
http://www.usb.org/developers/devclass_docs/pos1_02.pdf
).
Features:
•
HID based, no custom driver required
•
Much faster than keyboard emulation and traditional RS-232
•
Symbology identifiers (AIM and Hand Held Products) are always contained in the input report, which uses USB
direction names: input (to the PC) and output (to the device)
Scan the following bar code to program the imager for a HID POS interface.
Access the Device in Your Program
CreateFile opens the device as a HID, then ReadFile delivers the scanned data to the application. Use WriteFile to send data
to the device.
For complete information on USB and HID interfaces, please see
www.USB.com
or refer to one of the following manuals:
USB Complete, by Jan Axelson, ISBN: 096508919-3-1(
www.lvr.com
)
USB Design By Example, by John Hyde, ISBN: 0-471-37048-7(
www.wiley.com/compbooks
).
Getting Scanned Data
After scanning and decoding a bar code, the device sends the following input report:
Bit
Byte
7
6
5
4
3
2
1
0
0
Report ID = 2
1
Length of the bar code (field "Decoded Data")
2
AIM Symbology Identifier 0 (always ']')
3
AIM Symbology Identifier 1
4
AIM Symbology Identifier 2
5-60
Decoded Data (1-56)
61
Hand Held Products Symbology Identifier
62
Reserved
63
-
-
-
-
-
-
-
Decode
Data
Continued
