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User Instructions for the
USB-311 and USB-312 "SmartWye"™ PC USB Keyboard Encoders

DESCRIPTION

The "SmartWye"™ PC USB Keyboard Encoders make it easy to convert switch or contact closures to standard USB keyboard codes for input to a PC's USB port. The USB keyboard encoders enumerate as a standard HID keyboard, and support USB bus suspend and remote wake-up. If enabled by the USB host, an input contact closure will generate a remote wake-up signal on the USB bus. The USB Encoder model USB-312 contains an on-board USB hub providing an input for an USB peripheral. If any device is connected to the hub, its current draw must not exceed 400 mA.

OPERATION

The encoder detects and debounces switch closures, generates appropriate key codes, and sends them to the PC. When the switch is opened, the encoder sends a code indicating that the key is open.

GENERATED CODES

The USB Keyboard Encoder can generate one of four different USB keyboard code output configurations, selected by settings of jumpers JP3 and JP4. Jumpers MUST BE set prior to applying power to USB Keyboard Encoder for correct keyboard code configuration outputs. The USB codes generated are shown in the table below:

 Jumper JP3

Jumper JP4 

Keyboard Code Configuration 

Not Installed

Not Installed
 USB-311/312 Matrix Key Codes, see Table 2

Installed

Not Installed
 USB-311/312 Function Key Codes, see Table 1, column -24F

Not Installed

Installed
 USB-311/312 Numeric Key Codes, see Table 1, column -24N

Installed

Installed
 USB-311/312 Alpha Key Codes, see Table 1, column -24A

The keyboard code generated for a given switch closure is shown in the two tables (maps) below in terms of US keyboard key cap legends. J3 is the switch input connector to the USB PC keyboard encoder.

The first table, Table 1, shows three standard maps for the keyboard encoder models that accept up to 24 discrete contact closures to ground. The key code is generated when the J3 pin in the table is closed to the GND pin. The "A" (ALPHA) map generates mostly alphabetic keys, the "F" (FUNCTION) map generates functions keys, and the "N" (NUMERIC) map generates numeric keys.

Table 2 applies to matrix-connected switches, such as found on many membrane keypads. The matrix configuration of the keyboard encoder contains the complete Windows 104 keys of the standard PC keyboard with switches connected in an 8 by 13 matrix.

PREPARE FOR OPERATION

In order to assure proper operation of the "SmartWye", certain conditions should be observed in its application. The following is a list of these conditions:

ALL CONNECTIONS SHOULD BE MADE WITH THE PC POWER OFF!!

1. Set-up: You can connect the "SmartWye" USB Keyboard Encoder to the PC at any time (plug-and-play). You do not have to power-down the PC to make this connection. Use a standard USB Type A-B cable (may be purchased separately from Vetra) to connect the keyboard encoder to any convenient USB port on the PC. The USB Keyboard Encoder is powered from the PC via this cable. After plug-in, the Pc takes a short time to recognize (enumerate) the USB Keyboard Encoder; then the USB Keyboard Encoder is ready for operation. Jumpers (JP3 and JP4) must be set prior to applying power to the encoder board for correct keyboard code configuration. To set the encoder for a different key code output configuration, the encoder must be unplugged from the PC, jumpers reconfigured and than plug the encoder back into the PC.

2. Alternative host connection: Connection via the J1 connector location is provided if a connection other than USB Type A-B cable is required. Vetra does not manufacture an Interface cable for this connection. (See the pin out information at end of these instructions for connections to J1).

3. Hub Connection (USB-312 Encoders only): Connect an USB keyboard or any low or full-speed USB device to the built-in USB hub on the encoder at connector J6. The device can be connected at any time. The PC takes a short time to recognize (enumerate) the device, and then is ready for operation. The total current draw of the device connected to the hub must not exceed 400 mA.

4. Alternative Hub connection: Connection via the J2 connector location is provided if a connection other than USB Type A connection is required. Vetra does not manufacture an Interface cable for this connection. (See the pin out information at end of these instructions for connections to J2).

Table 1
Encoding Map for USB-311/312-24 Configurations
(Code generated when a J3 pin is connected to Ground)

Model

-24A

-24F

-24N

J3 PIN #

ALPHA

FUNCTION

NUMERIC

1

a

ESC

NUM /

2

b

F1

NUM *

3

c

F2

NUM -

4

d

F3

NUM +

5

e

F4

NUM ENTER

6

f

F5

NUM 0

7

g

F6

NUM 1

8

h

F7

NUM 2

9

i

F8

NUM 3

10

j

F9

NUM 4

11

k

F10

NUM 5

12

l

F11

NUM 6

13

m

F12

NUM 7

14

n

LF SHIFT

NUM 8

15

o

SPACE

NUM 9

16

p

ENTER

NUM .

17

q

PG UP

UP ARROW

18

r

PG DN

DN ARROW

19

s

UP ARROW

LF ARROW

20

t

DN ARROW

RT ARROW

21

u

LF ARROW

LF SHIFT

22

SPACE

RT ARROW

LF ALT

23

LF SHIFT

z

LF CNTL

24

ENTER

y

ESC

25

COMMON

COMMON

COMMON

Table 2
Encoding Table for USB-311/312 Matrix Configuration

J3 PINS

8

7

6

5

4

3

2

1

9

NUM 0

NUM 1

NUM 2

NUM 3

UP ARROW

DN ARROW

LF ARROW

RT ARROW

10

NUM 4

NUM 5

NUM 6

NUM 7

ESC

L SHIFT

LF ALT

LF CTL

11

NUM 8

NUM 9

NUM ENT

NUM .

F1

F2

F3

F4

12

NUM +

NUM -

NUM *

NUM /

F5

F6

F7

F8

13

a

b

c

d

k

l

m

n

14

e

f

g

h

o

p

q

r

15

i

j

INS

DEL

s

t

u

v

16

HOME

END

PAGE UP

PAGE DOWN

w

x

y

z

17

F9

F10

F11

F12

,

.

/

[

18

1

2

3

4

]

`

TAB

NUM LK

19

5

6

7

8

SCR LK

CAPS LK

-

=

20

9

0

ENTER

BK SP

\

;

`

SPACE

21

WINAPP

RTWIN

LFTWIN

PRT SCR

PSE

RT SHIFT

RT CNTL

RT ALT

22
               

23
               

24
               

25
               

The "Smart-Wye" USB Keyboard Encoders also support Num Lock, Caps Lock, and Scroll Lock status indicating LED's. By adding the J4 header, the "Smart-Wye" USB Keyboard Encoders can be configured to support keyboard indicator LED's. The encoders will source 2 mA on the folowing pins:

J4-1     Scroll Lock
J4-2     Caps Lock
J4-3     Num Lock

Pin Out Information for J1 and J2 connections to the USB-311/312 USB Keyboard Encoders

J1-1 Vcc J2-1 Vcc
J1-2 USB D- J2-2 USB D-
J1-3 USB D+ J2-3 USB D+
J1-4 Not Used J2-4 Not Used
J1-5 Shield J2-5 Shield
J1-6 Gnd J2-6 Gnd

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