Worth Data F52 User manual

WDR Table of Contents
Introduction................................................................................................1
Installation .................................................................................................2
Configuring the WDR Reader ...................................................................8
Scanning Techniques............................................................................9
Using The WDR Setup Menu ..............................................................10
Test the Reader with your computer ...................................................24
Using the Bar Code Slot Scanner .......................................................25
Using the MagStripe Slot Scanner ......................................................26
Laser and CCD Scanners....................................................................27
Accumulate Mode ...................................................................................31
Function/Control Key Support.................................................................32
Polling......................................................................................................33
Troubleshooting ......................................................................................37
WDR Reader Cables and Pinouts ..........................................................40
Opening the WDR Case..........................................................................42
Jumper & Switch Settings .......................................................................43
Specifications for Code 39 ......................................................................45
Codabar Specifications ...........................................................................48
Code 128 Specifications .........................................................................49
Interleaved 2 of 5 Code...........................................................................51
UPC Specifications .................................................................................53
MSI/Plessey Specifications .....................................................................57
Code 93 Specifications ...........................................................................59
PC Terminal Mode ..................................................................................60
WDR Setup Menu ...................................................................................62
Index........................................................................................................69
06/06
© Copyright 2006, Worth Data, Inc.

1
Introduction
Worth Data's WDR Readers are versatile serial bar code readers designed for use
with all micro and minicomputers. Features of the WDR Reader include:
• The WDR Model R22 can be attached between your computer and a
terminal, sending bar code data along with keyboard data with LINUX,
UNIX and PICK.
• Up to 32 WDR R22 Readers can be connected to a dedicated serial port,
with each unit accessed separately through polling from your computer.
• The R22 WDR can be ordered a variety of scanners including:
• Hand-held laser scanners,
• CCD Scanner.
• Bar code slot badge or wand scanner, and
• MagStripe scanners,
• The WDR Reader automatically reads and discriminates between Code
39, Full ASCII Code 39, 2 of 5, I 2 of 5, UPC-E, UPC-A, EAN-8, EAN-
13, Codabar, Code 93, MSI, Plessey, RSS-14, LabelCode 4&5,
StorageTek Tape Code, Code 128, UCC-128, and EAN-128.
• The WDR Reader is easily configured for your system by scanning menu
setup bar codes. For almost all applications no switch setting or opening
of the reader's case is required.
If you are installing the WDR Reader on a dedicated PC serial port (as opposed to
installing it between a PC serial port and a terminal) you should consider Worth
Data’s program PortKey.
PortKey is a Windows program that automatically takes bar code data from the
serial port and places it into your PC's keyboard buffer, making the WDR the
functional equivalent of a "wedge" type reader. Otherwise, you must explicitly
read the serial port as a separate device. PortKey also has the capability of
automatic background data collection from 1 to 32 WDR Readers. As you use
your Windows System for word processing, spreadsheets or any other application
programs, PortKey runs transparently in the background, collecting data from
your WDR readers, time and date-stamping the data, and storing it on your hard
disk.

2
Installation
Components of WDR Reader:
The contents of your WDR Reader shipment should include the following:
1) A WDR R22 decoder box plus:
a. Velcro strips which can be used to conveniently attach the reader to
the side of your computer, monitor or desk.
b. If ordered, one of the appropriate serial Cable Selections:
F34 ....... null-modem female DB-25 cable
F36....... straight-through female DB-9 cable
F45-1.... serial “Y” cable for connection between terminal and host
(See page 42 for pin-outs and longer descriptions)
c. A scanner (F52 wand, LI50 CCD, LZ300 Laser or LZ400 Laser)
d. A scanner holder.
e. A 5-volt power supply (Don't use a non-Worth Data power
supply; it will fry the board!).
f. A laminated Reader Setup Menu sheet (or slot scanner card deck)
g. A CD-ROM with the Windows WDR Test Program on it.

3
Connect the scanner to the WDR Reader:
Insert the scanner's telephone-style connector into the WDR Reader's scanner port.
You'll hear a click when it is properly inserted. (If you have a MagStripe slot
scanner, see page 27 for its installation instructions.)
Connect the power adapter to the WDR Reader & to an outlet:
Be certain to only use a Worth Data power supply; any other power supply will
likely fry the reader. Insert the power jack into the WDR Reader's power
connector, and plug the other end into an electric outlet. You'll hear three beeps as
the reader performs its self-test, and the LED will flash red to green.

4
Installing the WDR Reader with a dedicated serial port
The WDR Reader can be directly attached to a spare serial port as shown below.
Your software will need to read the serial port as a separate device, unless you're
using an IBM-compatible computer and Worth Data’s PortKey software, which
makes serial-port data look to your computer as if it had been typed at the
keyboard.
If you specified a 25-pin null-modem cable (part number F34) or a 9-pin cable
(part number F36) when you placed your order, you can cable directly from the
“SERIAL” port to the matching serial port on your computer.

5
Installing the WDR Reader between a Host and Terminal
If you attach the WDR R22 Reader between your computer and a terminal, as
shown below, using the F45-1 Serial Y Cable, bar code data will display on the
terminal as if it had been typed.
The F45-1 Serial Y Cable assumes you already have a dumb ASCII terminal
connected to a host computer. Unplug the host cable from the terminal and plug it
into the DB25 Female cable end on the F45-1 cable. Connect the other 25 pin end
of the F45-1 Y Cable to the terminal (where the host cable was plugged
previously). The WDR R22 now sits in-between the terminal and host acting as a
wedge reader; data scanned is echoed back by the host to the terminal screen.
The WDR reader must be configured so that the Baud Rate, Data Bits, Stop Bits
and Parity match the settings on the terminal. You may need to consult your
terminal’s documentation to determine how those settings are viewed on the
terminal. Once you know what the settings are, you can use the WDR Setup
Menu to make any necessary changes.

6
"Daisy-Chain" Attachment
"Daisy Chaining" allows many readers to be used with a single serial port.
Each WDR R22 Reader uses one F45-1 Serial Y Cable plugged into it’s SERIAL
port. A straight 25pin- to-25pin serial cable is used to go from Y cable to Y cable
(see the diagram below).
With three, four, or more readers, repeat this step to connect the second to the
third, the third to the fourth, and so on, until all readers are "daisy-chained"
together. These daisy-chain cables are straight 25 pin male-to-female serial cables
that can be found in many different lengths.
Depending upon the configuration of the serial port on your computer, you may
need to rewire the DB-25 or DB-9 end of the supplied serial cable, use a "gender
changer" or "null-modem adapter" (available at computer stores). See pages 42
and 43 for cable pin-outs.
Follow these instructions to connect and configure your WDR Readers for polling.
Connect the Worth Data power supplies to the WDR readers and plug the power
supplies into your outlets. You should hear three beeps as each WDR Reader is
plugged into the wall.
Setup each WDR Reader to the communications and bar code configuration you
want to use using the bar coded WDR Reader Setup Menu. Each WDR Reader

7
must be assigned a unique ID. The IDs for a WDR Reader and any other Worth
Data readers on the same port must be limited to ASCII values 96-127.
To set the ID character on a WDR reader, scan the Start Setup and then Set ID
Character bar codes from the WDR Reader Setup Menu. On the reverse side
of the Setup menu is a bar code menu titled Full ASCII Menu. Scan the code for
the ID (ASCII 96 - 127 is the last two columns on the Full ASCII Menu) you want
to give that WDR Reader, (i.e., to give the WDR Reader an ID of a, scan the bar
code below the lower case letter a). Turn the sheet back over and read End
Setup. Repeat this process for each of your WDR Readers, assigning a different
ID character to each one. See page 35 for a complete discussion of polling plus
sample polling programs in source BASIC.

8
Configuring the WDR Reader
for your computer and application
Find the 8 1/2 x 11" laminated WDR Reader Setup Menu
sheet and look it over. This simple menu lets you easily
configure the WDR Reader to work with almost any
computer system, and to tailor its bar code reading and data
format characteristics.
Be sure to read the scanning instructions on the next page.
To read Reader Setup Menu bar codes and configure your
reader, you must know the right way to scan bar codes.
These are the WDR Reader's default settings and are shipped configured to these
settings; they can be reset to them at any time by scanning the Start Setup and
Reset codes on the Reader Setup Menu.
Code 39 Enabled
Accumulate Mode enabled Check digit disabled
Start/stop characters not transmitted Caps Lock Off
2 of 5 Code Disabled
I 2 of 5 Code Disabled
6-digit code length Check digit disabled
UPC and EAN Enabled
UPC supplemental disabled UPC-E Compressed and NSC of 0
UPC-A NSC and EAN-13 1st 2 characters and check digits transmitted
UPC-E NSC and EAN-8 1st 2 characters & check digits not transmitted
Codabar Disabled
Start/stop characters not transmitted CLSI Format disabled
MSI/Plessey code Disabled
Check digit(s) not transmitted
Code 128 Enabled
UCC/EAN-128 options enabled
Code 93 Disabled
Full ASCII disabled
General configuration settings
RS-232 ASCII data format Full ASCII disabled
CR/LF terminating character No ID character
No intercharacter delay No MagStripe slot scanner
Data Transmission Timing of None Medium Beep pitch
No preamble or postamble 9600 Baud Rate
USA keyboard None Parity
8 Data Bits, 1 Stop Bit Full Duplex Transmission
No Protocol Host Response Disabled
No Aiming Dot

9
Scanning Techniques
Follow these instructions for proper scanning -- to read the Reader Setup Menu
bar codes and configure the WDR Reader, you must know the right way to scan
bar codes.
Wand scanners
Start in the white space (quiet zone) to the left or right of the bar
code.
Hold the wand as if it were a pencil, with about a 30-degree tilt
from perpendicular to the label. You can scan in either direction.
Also, for very high density codes, the wand should be held more
perpendicular to the bar code surface.
Quickly (3 to 30 inches per second) and lightly draw an imaginary
line through the entire bar code. Don't go slow or press hard -
neither makes it any easier to read.
Don't stop in the middle of the code. Move the and smoothly
across the entire bar code, stopping when it reaches the white
space (quiet zone) to the right of the bar code.
Stay within the code throughout the entire scan. Do not move
the wand's tip above or below the lines of the bar code.
Bar code slot badge scanners
For a bar code slot scanner, take the card for
the reader setup menu configuration bar code
that you need and turn it so the bar code is
facing the lighted side of the scanner. Make a
continuous swiping motion through the slot in
either direction.

10
Laser And CCD Scanning Instructions
Using a laser or CCD scanner is basically as simple and intuitive as "point and
shoot" at a distance of .5 - 24", depending on the scanner and the density of the
bar code.
Basically, the CCD and laser scanner's beam must cross every bar and space on
the bar code, without touching any other bar codes, as shown in the first example
below. For laser scanners, hold the scanner further away to produce a wider beam
for large bar codes, and closer for narrower bar codes.
Even though momentary exposure to a laser's low-power, visible-light is not
known to be harmful, you should not aim the beam into anyone's eyes.
The important thing to remember about using a laser or CCD with the WDR
Reader Setup Menu is that you need to make sure the scanner's beam covers only
one bar code at a time. The scanner's beam is wide enough, and the configuration
bar codes close together enough, that you will need to use your fingers, or the
supplied Laser Setup Assist window, to "block off" bar codes adjacent to whatever
configuration bar code you need to read.
For example, to read
this "5" bar code on the
WDR Setup Menu, you
would need to cover
any adjacent bar codes
with paper or a finger
first, as shown.
Using The WDR Setup Menu
1. To configure your reader using the Reader Setup Menu, you must first scan
the Start Setup code at the top left corner (or off the setup card deck
provided with slot scanners). Do this now. You'll hear two beeps. During
Setup, nothing will be transmitted to your computer; the Reader Setup Menu
codes are strictly for configuring the reader. If you did not hear two beeps,
try scanning the code again, until you hear the two beeps. If you've never

11
scanned bar codes before, read the scanning instructions on pages 10-11
before continuing.
2. Next, choose the topic you want to change an option for, and scan its code.
Let's use Beep Tone, at the lower left corner of the menu, as an example.
Scan the Beep Tone code now. You'll hear two beeps.
3. Then, choose the option you want to change, from the list next to the topic bar
code you just scanned. For Beep Tone, the options range from 0for the
lowest pitch to 4for the highest pitch. Using the "Barpad Table" on the right
side of the Reader Setup Menu, scan the number or letter associated with the
option you have selected. Let's change the beep pitch to Highest. Now scan
the 4on the "Barpad Table". You will again hear two beeps.
4. Now scan End Setup (at the top-right corner of the Reader Setup Menu to
complete the setup exercise. You'll hear three beeps, (on the Base Stations or
2-Way Laser). If you followed the instructions correctly and successfully
changed beep tone to "highest", the three beeps will be higher in pitch than
the other beeps had been. If they aren't higher in pitch, repeat the steps on
this page until you are successful at changing the beep tone.
Now that your beep tone is at the "highest" pitch, you may want to change it back
to "medium" or a different setting. Repeat the steps above, selecting the option
you prefer to "highest" in step 3.
When you've successfully changed the beep pitch, and are ready to configure the
reader for your specific application, scan Start Setup again. Continue scanning
topics and options until you've made all the changes you desire, and then scan
End Setup to complete setup. For keyboard models, pay attention to Keyboard
Country, Computer Interface, and Data Transmission Timing. For serial models,
pay attention to Baud Rate, Parity, and Data Bits.
The following pages will show you all of the configuration settings with default
settings in bold (default settings are marked with an *on the WDR Reader Setup
Menu).

12
Beep Tone
Lowest 0
Low 1
Medium 2
High 3
Highest 4
No Beep, No Laser Good LED 5
No Beep, but Laser Good LED 6
No Aiming Dot for LZ400-D 9
1 Second Aiming Dot A
2 Second Aiming Dot B
3 Second Aiming Dot C
4 Second Aiming Dot D
5 Second Aiming Dot E
6 Second Aiming Dot F
Code 3 of 9 (Code 39)
Enable Code 39 0
Disable Code 39 1
Enable Full ASCII Code 39 2
Disable Full ASCII Code 39 3
Enable Code 39 Accumulate Mode 4
Disable Code 39 Accumulate Mode 5
Enable Start/stop character transmission 6
Disable Start/Stop character transmission 7
Enable Mod 43 Check Digit 8
Disable Mod 43 Check Digit 9
Enable Check Digit Transmission A
Disable Check Digit Transmission B
Caps Lock ON C
Caps Lock OFF D
For information about Code 39 and Full ASCII Code 39, see Appendix D.
See page 33 for information about Accumulate Mode.
Enabling Start/Stop character transmission means that the WDR Reader will
transmit the *Start/Stop characters to your computer along with the data. For
example, data of 1234 would be transmitted as *1234*.
Enabling the Mod 43 Check Digit requires the units position of your data to
match the calculation for the check digit explained in Appendix D.
If you've enabled the check digit, enabling Check Digit transmission causes the
reader to transmit it to your computer along with the bar code data.

13
"Caps Lock ON" means that for all codes lower case letters read as data will be
transmitted as upper case, and upper case as lower. Numbers, punctuation &
control characters are not affected.
"Caps Lock OFF" means that letters will be transmitted exactly as read.
UPC/EAN
Enable UPC/EAN 0
Disable UPC/EAN 1
Enable UPC/EAN Supplements 2
Disable UPC/EAN Supplements 3
Enable transmission of UPC-A NSC and EAN-13 1st 2 4
Disable transmission of UPC-A NSC and EAN-13 1st 1 digits 5
Enable transmission of UPC-A and EAN–13 Check Digit 6
Disable transmission of UPC-A and EAN-13 Check Digit 7
Enable transmission of UPC-E NSC and EAN-8 1st Digit 8
Disable transmission of UPC-E NSC and EAN-8 1st Digit 9
Enable transmission of UPC-E and EAN-8 Check Digit A
Disable transmission of UPC-E and EAN-8 check Digit B
UPC-E Compressed C
UPC=E Expanded D
EAN-8 observes 9 & A above E
EAN-8 is forced to transmit 8 digits F
UPC-A transmitted in UPC-A format (see below)
UPC-A transmitted in EAN-13 format (see below)
ISBN conversion disabled (see below)
ISBN conversion enabled (see below)
For more information on UPC and EAN, see following page and Appendix H.
Enabling supplements allows you to read 2 and 5-digit supplemental codes used
with magazines and books. This disallows right-to-left reading of UPC codes,
to assure that the supplement doesn't get skipped. This setting also allows for
reading of the UCC/EAN 128 Extended Coupon Code. The Extended Coupon
Code consists of a UPC (must have NSC of 5) or an EAN (NSC of 99) code along
with a Code 128 supplemental code right next to it. This setting allows you to read
the Code 128 supplement as long as the correct NSC characters are present in the
UPC or EAN code.
Enabling transmission of UPC’s NSC or EAN country codes (leading digits, 1
for UPC; 2 for EAN-13) or Check Digits means that these digits will be
transmitted to your computer along with the rest of the UPC or EAN data.

14
UPC-E Compressed Format transmits UPC-E codes as is; Expanded Format
adds zeros to make them the same length as UPC-A.
UPC-E can be used in either normal UPC-E format (implicit NSC of 0) or UPC-
E1 format (NSC of 1). UPC-E1 is enabled by wanding 2 of 5 Code and 8 (9
disables UPC-E1). It is very easy to partially read EAN-13 as UPC-E1, so don't
enable UPC-E1 if reading EAN-13.
If you wish to transmit UPC-A data in EAN-13 format, (an added leading 0 for
the USA's country code), wand Terminator Character and F. Wanding E, the
default, sets UPC back to no country code transmitted.
Enable supplements to read 2 and 5-digit supplemental codes used with
magazines and paperbacks. This disallows right to left reading of UPC codes,
assuring that the supplement doesn't get skipped.
ISBN, International Standard Book Numbering, bar codes are EAN-13 codes with
a 5 digit supplement. If the first three digits are the "Bookland" country codes of
978 for books or 977 for periodicals, then you can enable transmission of EAN-13
bar codes in the ISBN format. Suppose you scan an EAN-13 with 5 digit
supplement which is a bar code of 978055337062153495. It would be transmitted
in ISBN format as 0553370626. 055337062 are the first nine digits of the ISBN
format, and 6 is the newly calculated Mod-11 check digit.
To enable the transmission of the ISBN format, scan Terminator Character
and D. Scanning C, the default setting, disables conversion to ISBN format back
to regular EAN-13 format.
MSI and Plessey
Disable MSI 0
Enable MSI with 1 Mod 10 check digit 1
Enable MSI with 2 Mod 10 check digits 2
Enable MSI with 1 Mod 11 and 1 Mod 10 check digit 3
Transmit No MSI Check Digits 4
Transmit 1 MSI Check digit 5
Transmit 2 MSI Check digits 6
Enable Plessey (mutually exclusive with MSI) 7
Enable LabelCode5 8
Enable LabelCode4 9
For more information about MSI code, see Appendix I.

15
Codabar
Enable Codabar 0
Disable Codabar 1
Enable CLSI Codabar 2
Disable CLSI Codabar 3
Enable Start/Stop Character Transmission 4
Disable Start/Stop Character Transmission 5
For information about Codabar, see Appendix E.
CLSI format is a form of Codabar often used by libraries.
Enabling Start/Stop character transmission means that the WDR Reader will
transmit start/stop characters to your computer along with data. If you're varying
start/stop characters with different label types, you'll want to enable transmission.
Code 128
Disable Code 128 0
Enable Code 128 1
Disable UCC/EAN-128 2
Enable UCC/EAN-128 3
Enable Storage Tek Tape Label Code C
Disable StorageTek Tape Label Code D
Bar Code IDs transmitted E
Bar Code IDs not transmitted F
Bar Code ID characters can be transmitted as a leading character to identify the
bar code symbology type scanned. To enable a Bar Code ID character (a for
Codabar, b-Code 39, c-UPC-A, d-EAN-13, e-I2of5, f-2of5, g-128, j-MSI, i-93, n-
UPC-E0, o-UPC-E1, p-EAN-8, x-Plessey, y-LabelCode4, z-LabelCode5, s-STK)
to be transmitted at the beginning of each bar code read, wand E.
To disable bar code ID characters, wand E.
For information about Code 128, see Appendix F.
RSS-14
Disable RSS-14 0
Enable Standard 14 digits 1
Enable 14 plus Identifiers 2
Enable 14 plus UCC 128 Emulation 3
By default, standard RSS-14 is disabled, scan 1 to enable. Options 3 and 4 enable
the alternate RSS-14 formats. For more information on RSS-14, see the AIM
website at http://www.aimglobal.org/standards/symbinfo/rss_overview.asp

16
2 of 5 Code
Enable Interleaved 2 of 5 0
Disable Interleaved 2 of 5 1
Enable Interleaved 2 of 5 Check Digit 2
Disable Interleaved 2 of 5 Check Digit 3
Enable Check Digit Transmission 4
Disable Check Digit Transmission 5
Enable Standard 2 of 5 6
Disable Standard 2 of 5 7
For information about Interleaved and Standard 2 of 5, see Appendix G.
Enabling the Check Digit requires the data's units position to match the
calculation for the check digit explained in Appendix G. If you've enabled the
check digit, enabling Check Digit transmission causes the reader to transmit it to
your computer along with the bar code data.
2 of 5 Data Length
2 of 5 Code is so susceptible to interpreting partial scans as valid reads that
the Radio/Freedom Reader uses fixed-length data as a safeguard. To choose a
data length, scan it as a two-digit number using the Barpad Table. For example,
to select 8-digit data length, you would scan a 0 and then an 8. Because
Interleaved 2 of 5 is required to be an even number of digits in length, you
must use an even number. If you're unsure of your bar code length, temporarily
set the length to 00, read a bar code, and count its digits and then set it to the
actual length. DO NOT PERMANENTLY SET THE 2 of 5 LENGTH TO 00
or you will get misreads!
Code 93
Enable Code 93 0
Disable Code 93 1
Enable Full ASCII Code 93 2
Disable Full ASCII Code 93 3
For more information on Code 93 see Appendix J.

17
Inter-character delays
None 0
Short 1
Short Medium 2
Medium 3
Long 4
The WDR Reader can transmit bar code data with five different inter-character
delay rates (this is independent of baud rate). Most computers work perfectly with
no delay, but with the wide variety of systems out there we have to provide some
delay rates. Older minicomputers in particular expect delays with “keyed” data.
Baud rate
300 0
600 1
1200 2
2400 3
4800 4
9600 5
19,200 6
Sets the baud rate according to the baud rate your terminal, or the baud rate you
want to use with your serial port.
Data bits
7 Bits 0
8 Bits 1
Set the data bits ("word length") to the same setting your terminal is using, or you
want to use with your serial port.
Parity
None 0
Even 1
Odd 2
Set parity to the same setting your terminal is using, or the one you want to use
with your serial port. None is usually used in conjunction with 8 data bits; Even
or Odd with seven data bits.

18
Stop bits
1 Bit 0
2 Bits 1
Set the stop bits to the same setting your terminal is using, or you want to use with
your serial port.
Protocol
None 0
XON/XOFF 1
ACK/NAK 2
Polled – No ACK/NAK 3
Polled with ACK/NAK 4
Host Response Enabled 5
Host Response Disabled 6
"None"
means that the WDR will transmit bar code data to the computer without waiting
for a request or response. Unless you're connecting multiple readers to one serial
port, you'll probably want to select "None" protocol.
"XON/XOFF"
XON/XOFF protocol should be used only with a single WDR Reader connected
to a dedicated serial port. Don't use it if your Reader is connected between a
computer and terminal. XON/XOFF lets your computer disable and enable bar
code reading, allowing the computer to perform time-consuming tasks with no
data loss. The computer sends the WDR an XOFF (ctrl-S) when busy, and an
XON (ctrl-Q) when ready to receive bar code data again. On receipt of the XON,
the WDR's LED changes to red, and bar code reading is disabled. When the
computer sends the XOFF, the reader resumes normal operation and its LED
returns to green.
"ACK/NAK"
protocol can be used to confirm data accuracy, (especially with long RS-232
cables). With ACK/NAK selected, the reader appends a checksum to the end of
the data, and waits for an ACK (control-F) or NAK (control-U) from the host
before reading any more codes or turning its LED back to green. The WDR
calculates a checksum by 1) XOR-ing the data to a single byte, 2) expanding the
resulting byte to 2 bytes. i.e., suppose we are transmitting the data 123 followed
by a Carriage Return. The WDR XOR's the three bytes (the "123") to Hex 30; the
high order nibble is transmitted as 33, and the low order nibble is transmitted as
30. The computer must calculate the checksums exactly the same way as the

19
WDR and then compare its calculated checksums with the ones received from the
WDR. If they match, the computer transmits an ACK back to the WDR; if they
don't match, the computer transmits back a NAK to the WDR. When the reader
receives an ACK or NAK, or times out, its LED returns to green. The reader does
not beep for an ACK, but produces two long beeps for a NAK or time-out. Set
time-out duration with Host Response Delay, described on page 23.
"Polled - No ACK/NAK"
causes the WDR to wait for the host to poll it (send that particular Reader's ID
character, and a CR) before transmitting bar code data. This applies only to
multiple readers connected to one serial port and is not the preferred method,
which is "Polled with ACK/NAK" described below and has an example program
on page 36. See page 35 for detailed explanations of polling.
"Polled with ACK/NAK"
After being polled with its ID, the WDR transmits the bar code data with a
checksum appended. The host then calculates the checksum characters (see
"ACK/NAK" on the previous page for the details), and compares it with the two
checksums received. If they're the same, the host sends that reader's ID and an
ACK. If different, the host sends the ID and a NAK. When the reader receives
its ID and the ACK or NAK, or if it times out, its LED returns to green. The
reader doesn't beep for an ACK, but produces two long beeps for a NAK or time-
out. Set time-out duration with Host Response Delay, described on page 23. For
a sample program to perform Polling with ACK/NAK, see page 37. See page 35
for detailed explanations of polling.
"Host Response Enabled
gives the host computer the power to cause the Reader to emit two different types
of beeps, and its LED to flash orange, by sending a control character out the serial
port to the reader. Especially if the reader is some distance from the computer so
the person reading bar codes doesn't see the screen, you may want to use this
feature to signify that a code was or was not accepted and that it was read in the
proper sequence.
Sending a control-G (BEL - ASCII 7) to the reader produces one quick beep and
orange flash.
Sending a control-R (DC2 - ASCII 12 hex or 18 decimal) to the reader produces
two long beeps and a long orange flash.
To use "Host Response Enabled" mode with Polled or Polled with ACK/NAK
Protocol, the host computer needs to precede the BEL or DC2 with the ID
character of the WDR Reader they are intended for. "Host Response Disabled"
disables this ability.