PSC LM520 Owner's manual

R44-2016 (Rev. E)
LM520 Scanner
Integration & Programming Manual

R44-2016 i-1
Contents
The LM520 Bar Code Scanner
Overview .........................................................................................................................................................1
Unpacking the LM520..................................................................................................................................... 2
Scanner Care .................................................................................................................................................2
Mounting the LM520
General Considerations ..................................................................................................................................3
Mounting .........................................................................................................................................................3
Mounting the Scanner Stand-Alone................................................................................................................ 4
Integrating the Scanner to Read at the Proper Distance ................................................................................4
Integrating the Scanner Behind a Window .....................................................................................................5
Electrical Interface ..........................................................................................................................................8
Interface Cable Schematic....................................................................................................................... 9
LM520 Scanner Configuration
Configuration Management ..........................................................................................................................10
Programming Methods................................................................................................................................. 12
Programming through the Serial Interface .............................................................................................12
Programming with Bar Codes................................................................................................................ 13
Conventions ..................................................................................................................................................13
Setting Serial Communication Parameters................................................................................................... 14
Baud Rate ..............................................................................................................................................14
Data Format........................................................................................................................................... 15
Flow Control........................................................................................................................................... 16
Controlling Scanning Through Host Commands.......................................................................................... 17
Triggering Scanning Using Software Switch ..........................................................................................17
Triggering Scanning Using Hardware Switch ........................................................................................ 18
Continuous Scanning Mode ...................................................................................................................18
LaserSense Scanning Mode.................................................................................................................. 19
Canceling Software Triggered Scanning ...............................................................................................19
Setting Symbology Parameters.................................................................................................................... 20
Enabling All Symbologies ......................................................................................................................20
EAN ........................................................................................................................................................21
UPC .......................................................................................................................................................21
Code 128............................................................................................................................................... 22
Code ISBT 128...................................................................................................................................... 23
Code 93................................................................................................................................................. 25
Codabar .................................................................................................................................................25
Code 39 .................................................................................................................................................26
Interleaved 2 of 5................................................................................................................................... 27
Standard 2 of 5 ...................................................................................................................................... 28
Formatting Bar Code Data............................................................................................................................ 29
Preamble ................................................................................................................................................29
Postamble ..............................................................................................................................................29
Filters..................................................................................................................................................... 30
Field Descriptions ............................................................................................................................31
Pad Character .................................................................................................................................33
Edit Function ...................................................................................................................................33

R44-2016 i-2
Setting the Bar Code Format................................................................................................................. 34
Additional Commands.................................................................................................................................. 35
Good Read Beeper Duration .................................................................................................................35
Laser Timeout ........................................................................................................................................35
Double Read Timeout............................................................................................................................ 36
Read Verification ....................................................................................................................................36
No Read Message................................................................................................................................. 37
No Read Output Signal ..........................................................................................................................37
No Read Output Signal Mode 1 ......................................................................................................37
No Read Output Signal Mode 2 ......................................................................................................37
Diagnostic Commands ...........................................................................................................................38
Good Read LED Duration ......................................................................................................................38
Appendix A:Technical Specifications ...........................................................................................................A-1
Appendix B: Mechanical Specifications .......................................................................................................B-1
Appendix C: Factory Default Configuration .................................................................................................C-1
Appendix D: LM520 Programming Labels ....................................................................................................D-1
Appendix E: ASCII Conversion Table ...........................................................................................................E-1

R44-2016 i-3
List of Tables
Table 1. Electrical Interface Specifications ..........................................................................................8
Table 2. Configuration Commands .....................................................................................................10
Table 3. Baud Rate ..............................................................................................................................14
Table 4. Data Format ..........................................................................................................................15
Table 5. Flow Control .........................................................................................................................16
Table 6. Software Switch Control .......................................................................................................17
Table 7. Hardware Switch Control .....................................................................................................18
Table 8. Continuous Scanning Mode ..................................................................................................18
Table 9. LaserSense Mode ..................................................................................................................19
Table 10. Symbologies .......................................................................................................................20
Table 11. EAN ....................................................................................................................................21
Table 12. UPC .....................................................................................................................................21
Table 13. Code 128 .............................................................................................................................22
Table 14. ISBT Symbology ................................................................................................................23
Table 15. Concatenation Pairs ............................................................................................................24
Table 16. ISBT Commands ................................................................................................................24
Table 17. Code 93 ...............................................................................................................................25
Table 18. Codabar ...............................................................................................................................25
Table 19. Code 39 ...............................................................................................................................26
Table 20. Interleaved 2 of 5 ................................................................................................................27
Table 21. Standard 2 of 5 ....................................................................................................................28
Table 22. Preamble .............................................................................................................................29
Table 23. Postamble ............................................................................................................................29
Table 24. Filter Examples ...................................................................................................................30
Table 25. Symbology Identifiers ........................................................................................................32
Table 26. Pad Characters ....................................................................................................................33
Table 27. Edit Functions .....................................................................................................................33
Table 28. Bar Code Format .................................................................................................................34
Table 29. Beeper Duration ..................................................................................................................35
Table 30. Laser Timeouts ...................................................................................................................35
Table 31. Double Read Timeout .........................................................................................................36
Table 32. Read Verification ................................................................................................................36
Table 33. No Read Message ...............................................................................................................37
Table 34. No Read Output Mode ........................................................................................................38
Table 35. Diagnostic Commands ........................................................................................................38
Table 36. Good Read LED Duration ..................................................................................................38
Table A-1. Performance Specifications ...........................................................................................A-1
Table A-2. Power Requirements ...................................................................................................... A-2
Table A-3. Physical and Environmental Specifications .................................................................. A-2
Table A-4. Agency Approvals ......................................................................................................... A-2
Table C-1. Factory Default Configuration ........................................................................................C-1
Table D-1. Programming Labels .................................................................................................... D-1
Table E-1. ASCII Conversion Table .................................................................................................E-1

R44-2016 1
Section 1
The LM520 Bar Code Scanner
Overview
The LM520 scanner is a compact, decoded, single-line scanner for fixed position or embed-
ded applications, such as conveyor, library, document tracking, chemical analyzers, vending
machines, point-of-sale (POS) terminals, and other attended or unattended scanning appli-
cations. The LM520 is a complete scanning system, ready to plug in and scan. The LM520
presents a fast, easy and low-cost way to incorporate scanning into any application where
you need to read a bar code.
A typical system using the LM520 scanner consists of the scanner itself and a host system
such as a PC, POS system, or package sorting system. The host system controls the scanner
and receives the decoded bar code data produced by the scanner. The laser in the LM520
scanner emits coherent visible light. When a bar code passes through the scanner’s beam,
light is reflected off the bar code. The scanner collects this reflected light, processes it into a
digital signal and decodes it into data that can be used by the host system. In some cases the
data may be processed further by the scanner before being transmitted to the host.
The LM520 has four different operational modes which can be used to scan a bar code. The
four operational modes include:
• an external switch such as an output line from a Programmable Controller (also
known as a PLC) can be used to enable scanning
• software commands from the host system
• continuous scanning operations, and
• a unique PSC motion detection circuitry called LaserSense™. This circuitry allows
the LM520 to only scan when an object is passed in front of it.
The various modes are selected via host commands or special programming bar codes.

The LM520 Bar Code Scanner Section 1
2LM520 Scanner Integration & Programming Manual
Unpacking the LM520
The LM520 bar code scan scanner is shipped in custom packaging. Carefully open the
package, and remove the scanner from the packing material.
The LM520 standard configuration includes:
•LM520 scanner
•power supply
•mounting hardware (two bolt studs with nuts)
•interface cable - male DB9 (scanner side) [with optional beeper if ordered]
•diskette with this manual and other information
When you open the shipping carton, visually inspect the package’s contents. If any parts are
damaged or you need additional hardware, please contact your reseller or the PSC
Customer Support Center at 1-800-547-2507.
Scanner Care
The LM520 bar code scanner contains sensitive components which require special
handling. PSC Inc. may not warrant damage due to improper handling.
•Do not open the scanner’s case. Doing so will void the warranty.
•Avoid touching the front window. Fingerprints will degrade the scanner’s
performance.
•Only clean the scan window when visual inspection reveals dirt or residue.
Remove lint or foreign material be present with filtered clean air. Remove
fingerprints or other residue using clean, cotton-tipped applicators dipped in
isopropyl alcohol, or with soft tissues dipped in high-quality lens or eyeglass
cleaner. Do not reuse cotton-tipped applicators or tissues.
•Do not scrub the window.
•Never wipe the window with a dry tissue or applicator.

R44-2016 3
Section 2
Mounting the LM520
The LM520 bar code scanner is designed to be mounted to a stand in a fixed position. This
section describes the layout of the mounts for optimum scanner performance.
General Considerations
Although the LM520 bar code scanner has been designed to be impact-resistant, it is impor-
tant to consider the effect of the environment on the scanner. In particular, the mounting
scheme should minimize the possibility of foreign objects contacting the window’s surface.
Such contact will damage the window over time and reduce the scanner’s performance. The
mounting design should also take into consideration the clearance needed for the power
supply and interface cables. These cables should be routed away from the operator’s work-
ing area in attended applications.
Mounting
System integration is made easy with the LM520’s unique mounting design. Six mounting
grooves in the scanner’s sealed enclosure enable mounting on any one of four sides. When
looking at the back of the scanner, these slots are located as shown in Figure 1.
Figure 1. Mounting
Appendix B, Mechanical Specifications shows mechanical drawings of the precise position of
the mounting slots relative to the scanning laser beam.
6789
12345
Mounting Slots
Mounting Slots
1.00"
(2.54cm)
0.50"
(1.27cm)
0.50"
(1.27cm)
0.675"
(1.71cm)
0.675"
(1.71cm)
LM520 Scanner
Mounting Slots (6 total)

Mounting the LM520 Section 2
4LM520 Scanner Integration & Programming Manual
Mounting the Scanner Stand-Alone
For most instances using an adjustable mount is recommended. The position of the scan line
can be fine-tuned during actual installation and the scanner’s distance from the scanned
object can be easily changed. The location of the operator should also be considered for
attended applications. Care should be taken to position the scanner to minimize the possi-
bility of the operator overturning the scanner, spilling liquid on the scanner, inadvertently
unplugging the cables, and so on.
Integrating the Scanner to Read at the Proper Distance
When deciding how to mount the LM520, there are many criteria that must be considered.
First, there are minimum and maximum distances that the bar code can be from the front of
the scanner to properly read, depending on the size of the bar code. These distances, or
depth of field, are specified in Appendix A, Technical Specifications.
Second, the scanner must be positioned so that the bar code to be read is not “square”or
parallel to the front of the scanner. The scanner must have at least 3 degrees skew angle to
operate properly. See Appendix B, Mechanical Specifications for such information as skew,
pitch, and the scanner’s mechanical parameters.
Third, the scanner must be positioned so that the scan line will be long enough to cover the
entire bar code. The scan line should exceed the width of the bar code since only about 80%
of the scan line is usable (see Figure 2). Use the following formula to calculate the expected
usable line length (l) at a given distance (d):
l = [(d+0.88in) x 2 x tan (q)] x 0.8 (if d is measured in inches)
or
l = [(d+2.34cm) x 2 x tan (q)] x 0.8 (if d is measured in centimeters)
where
l = usable line length
d = distance from the front of scanner
q = half of the scan angle, (23°± 2.0°)

Section 2 Mounting the LM520
R44-2016 5
Figure 2. Mounting the Scanner
Integrating the Scanner Behind a Window
When the LM520 scanner is integrated into a larger system, additional factors must be taken
into account. The most important of these is an additional window placed between the
LM520 and the bar code to be read. While an additional window provides protection for the
LM520, it will also degrade the scanner’s performance due to the need for the laser light to
traverse two additional optical surfaces passing through to the bar codes, and the reflected
light returning. Following the instructions in this section will help optimize the amount of
outgoing light that reaches the bar code and the amount of reflected light that is collected by
the scanner.
The LM520 scanner emits a laser beam in the form of a scan line. The beam’s light exits the
scanner’s window and reflects off the bar code symbol. The reflected light returns through
the window, and is collected with a photodiode. As in any optical system, any type of win-
dow causes a reduction in the amount of light that exits or enters the scanner since some of
the laser light is lost due to surface reflection.
LM520 scanner
l = 80%
of scan line
d
.88"
2.34cm
q=

Mounting the LM520 Section 2
6LM520 Scanner Integration & Programming Manual
The design and placement of the window is critical for optimum system performance. The
following issues must be considered.
•The window must not block outgoing laser light.
•The window must not block laser light reflected from the bar code.
Figure 2 shows the minimum size and position of the window along the horizon-
tal and vertical axes, respectively. The minimum window size must increase as
the distance between the scanner and the window increases. This is necessary
to accommodate the width of the scan line.
•Reflections of outgoing laser light caused by the window or other reflective sur-
faces should not reach the front window of the scanner.
Determine the window tilt based on your application. The tilt angle of the window (that is,
its position relative to the optical axis or center-line) is important because a portion of the
emitted light will always be specularly reflected from each of the two window surfaces. This
reflected light must not reach the scanner’s window either directly or via multiple reflec-
tions from other parts of the system.
Figure 3. Tilt Angle
Nominal
Beam Path
d = 1.250"
31.74mm
0.880"
22.34mm
Angle = 103.7˚
0.125"
3.18mm
0.820"
20.83mm
Reflected light
Window
Angle = 90 + 0.5 [ arctan ( )] = 103.7
0.65
1.25

Section 2 Mounting the LM520
R44-2016 7
An example of acceptable system window inclination is shown in Figure 2. As can be seen,
moving the system window closer to the scanner makes it necessary to increase the window
angle with respect to vertical. Less inclination is necessary if the reflection is directed below,
rather than above the scanner, since laser light is emitted near the bottom of the scanner’s
window and collected near the top of the scanner’s window. If the light reflected from the
window will be deflected above the scanner, the required window angle (from horizontal) is
given by:
If the light will be deflected below the scanner, the required window angle (from horizontal)
is given by:
The window material you select depends on the anticipated environment and your
scanner’s intended use. Appropriate window materials include glass, sapphire, and plastic.
Glass, and especially sapphire, have adequate surface hardness for most applications.
However, if you use any type of plastic, it should have a protective hard-coat on the exposed
surface. The hard-coat will protect the plastic surface from damage if the system window
needs to be cleaned.
In addition to hard-coating, some window applications may require special treatment such
as antistatic or antireflection coatings. In general, do not use antiglare coatings due to
undesirable polarization and diffusion effects.
Angle = 90 + 0.5 [ arctan ( )] if d is measured in inches
0.65
d
Angle = 90 + 0.5 [ arctan ( )] if d is measured in cm
1.65
d
Angle = 90 - 0.5 [ arctan ( )] if d is measured in inches
0.2
d
Angle = 90 - 0.5 [ arctan ( )] if d is measured in cm
0.51
d

Mounting the LM520 Section 2
8LM520 Scanner Integration & Programming Manual
Electrical Interface
The LM520 scanner communicates with the host over a standard DB-9 connector. The
pinouts for the connector are shown in Table 1.
Table 1. Electrical Interface Specifications
Pin # Direction
(relative to
LM520) Signal Function
1 Output Beeper/
Good Read 1
1Beeper Drive/Good Read source current must be limited to 50mA with a maximum voltage of 5VDC.
5VDC output signal used to drive an audio indicator.
2 Output TX Serial asynchronous RS232C level data transmitted to the host. NRZ format and user programmable for wordformat and baud rate. (Default: 9600 baud,
8 data bits, no parity, 1 stop bit).
3 Input RX Serial asynchronous RS232C level data received from the host. NRZ format and user programmable for wordformat and baud rate. (Default: 9600 baud,
8 data bits, no parity, 1 stop bit).
4 Output No Read 2
2No Read output will source 15mA @ 5VDC. The maximum sink current must be limited to 200mA with a maximum voltage of 14VDC.
This signal is asserted at the end of a scanning cycle if no label is decoded
and will remain asserted until:
1. A successful decode occurs, or
2. A user specified timeout period elapses.
This may be configured in 100ms increments from 100 ms to 9900 ms
(9.9 seconds). Refer to the section titled No Read Output.
NOTE: If the timeout is used, the signal will be immediately deasserted if a
software scan command, hardware scan trigger on pin 9 or a LaserSense
scan occurs before the user specified time elapses. Setting a timeout is not
available in Continuous Scan mode.
5 Input Gnd Power supply/signal ground.
6 Input Vcc Power supply input voltage (4.75 - 12.0VDC)
7 Input CTS RS232C Clear to send control line.
8 Output RTS RS232C Request to send control line.
9 Input Scan Trigger 3
3Scan trigger signal must be limited to a maximum input voltage of 5VDC with a maximum input current of 10mA.
Ground on this input initiates bar code scanning. Scanning will continue
until either: (a) this line returns to high (5VDC) level, or (b) this line is dis-
connected, or (c) the programmed time period expires, or (d) a bar code is
decoded.

Section 2 Mounting the LM520
R44-2016 9
Interface Cable Schematic
The drawing in Figure 4 shows a schematic view of the electrical connection between the
scanner and the host.
Figure 4. Interface Cable Schematic
ORANGE
YELLOW
VIOLET
GREEN
RED
WHITE
BROWN
BLUE
1
2
3
4
5
6
7
8
9
3
2
7
4
5
1
23
DB25-S DB9-P
HOST END SCANNER END
Connector is a 2.5 mm stereo plug
for the scan trigger, no read signal
and power supply ground.
Power Supply
4.75 - 12VDC
Beeper
(if applicable)
BEEPER/GOOD READ
TXD
RXD
NO READ
GND
VCC IN
CTS
RTS
TRIGGER_IN

R44-2016 10
Section 3
LM520 Scanner Configuration
The LM520 offers a command interface which allows a wide range of customization. Com-
mands can be combined with standard programming bar codes to develop an active config-
uration and a saved or factory default configuration.
Configuration Management
The LM520 scanner always contains two configuration sets: the Active configuration and
the Factory Default configuration. Both configurations are stored in nonvolatile memory.
When the scanner receives a command changing the configuration, it changes the Active
configuration. If the scanner is reset to the Factory Default configuration, the factory
defaults are copied to the Active configuration. See Appendix C, Factory Default Configura-
tion for a concise list of the factory defaults.
The LM520 offers the ability to change and save a new Factory Default configuration. To
overwrite the Factory Default configuration as shipped from PSC, first make changes to the
Active Configuration, then store the Active Configuration as the Factory Default. The
previous Factory Default will be overwritten. Figure 5 illustrates this process. Table 2
describes the commands for changing the default configuration.
Table 2. Configuration Commands
Command Setting
Z1 Reset active configuration to factory defaults.
The active configuration will be overwritten.
Z2 Store the active configuration as Factory Default.
The contents of the Factory Default will be overwritten.

Section 3 LM520 Scanner Configuration
R44-2016 11
Figure 5. Configuration Management
Factory Default
Configuration
Host Serial Command
or
Programming Label
Active
Configuration
Z2
Z1
Z1 - Copy vaulted configuration into active configuration.
Z2 - Copy configuration from active configuration to the factory default configuration.

LM520 Scanner Configuration Section 3
12 LM520 Scanner Integration & Programming Manual
Programming Methods
The LM520 scanner may be programmed either by sending commands from a host over the
serial interface or by the using bar codes containing programmable commands. Typically,
the scanner is programmed over the serial interface when it is integrated into a system.
Appendix D, LM520 Programming Labels, contains a minimal set of programming
bar codes and the section titled, Programming with Bar Codes, on page13, describes how to
create programming bar codes.
Programming through the Serial Interface
The easiest and most common way to program the LM520 is by sending ASCII commands
through the serial interface. Each command transmission must begin with the STX (0x02
hex) and ESC (0x1B hex) characters. Next, the command itself is transmitted, followed by
any necessary parameters. The command transmission ends with an ETX (0x03 hex).
A complete serial command transmission, therefore, consists of:
STX-ESC-[command]-[parameters]-ETX
The scanner uses an ACK/NAK protocol to communicate with the host. The scanner does
not echo received data back to the host, and will not acknowledge transmissions which do
not begin with STX-ESC and end with ETX. Upon receipt of a valid command sequence,
the scanner responds in one of two ways:
•All commands that are valid (both commands and parameters) take the requested
action and then transmit an ACK to the host.
•If the command is invalid, the scanner responds with an ASCII NAK (0x15 hex).
All valid commands return an ACK. Otherwise, a NAK is returned if the command is not
valid. If the command is not formatted properly (missing the STX, ESC, or ETX), the scanner
does not respond. Each command recognized by the scanner consists of two ASCII charac-
ters, followed by any required parameters.

Section 3 LM520 Scanner Configuration
R44-2016 13
Programming with Bar Codes
The LM520 scanner can also be programmed by scanning bar codes which contain com-
mands. This method allows users to easily adjust scanner parameters.
Bar codes used for programming must be Code 128, with a Function Code 3 (FNC3) as the
first character. The command following the FNC3 character configures the scanner in
exactly the same way as if it had received the command over the serial line, except that the
scanner will not acknowledge the command on the serial line. Each bar code may contain
only one command. All parameters for the command must be included in the label with the
command characters. For example, the label to limit the minimum number of Code 39 to 5
characters would be.
<FNC3>OH05
The scanner can be programmed not to accept programming bar codes by using the Disable
Programming Bar Codes command (@Y). If you disable the programming with bar codes
feature, the scanner will still accept programming commands through the serial port. The
Enable Programming (@Z) bar code commands will always be accepted by the scanner, and
cannot be disabled.
If Disable Programming Bar Codes (@Y) is set, all programming bar codes except Enable
Programming Bar Codes (@Z) will be treated as standard Code 128 bar codes.
Conventions
The remainder of this manual presents the valid commands in a tabular format. These tables
contain two or three columns.
•First column – Bar Code Command, contains the two-letter ASCII string which
the scanner accepts as programming commands through the serial port or in a
programming label. See Appendix D, LM520 Programming Labels, for instructions
on how to create bar code programming labels.
•Second column –Bar Code Parameters, may be present. If an entry appears in this
column, a parameter setting is required to complete the command.
•Last column – Setting, describes the effect of the command and its associated
parameters.
•Default Entries –The factory default settings for the scanner are shaded and
denoted by asterisk.
A concise list of these defaults is presented in Appendix C, Factory Default Configuration.
³OH05

LM520 Scanner Configuration Section 3
14 LM520 Scanner Integration & Programming Manual
Setting Serial Communication Parameters
The first step in the integration process is establishing communications between the scanner
and the host. This is done by matching the scanner’s communications parameters to the
serial communication requirements of the host. The Baud Rate, Data Format and Flow
Control communication settings of the scanner must match the serial communications
requirements of the host. For example, if the scanner is sending data at the wrong baud rate,
the host will not be able to interpret the data that is being sent. The following section out-
lines the RS-232 communication settings.
Baud Rate
Use one of the commands shown in Table 3 to set the LM520 baud rate. Note that the scan-
ner and the host must communicate at the same rate for communication to be successful. An
ACK command will be sent by the scanner at the new baud rate, indicating that the com-
mand has been received and understood.
* Asterisk and shading denotes the Factory Default Setting.
Table 3. Baud Rate
Command Setting
DA Baud = 300
DB Baud = 600
DC Baud = 1200
DD Baud = 2400
DE Baud = 4800
DF * Baud = 9600
DG Baud = 19200
DH Baud = 38400

Section 3 LM520 Scanner Configuration
R44-2016 15
Data Format
These parameters control the data format in which the LM520 will communicate with the
host. Note that the scanner and host must communicate in the same format for communica-
tion to be successful. An ACK command will be sent by the scanner in the new format indi-
cating that the command has been received and understood. Table 4 lists the commands for
the data format options.
Table 4. Data Format
Command Setting
EC 7 data bits, 1 stop bit, even parity
ED 7 data bits, 1 stop bit, odd parity
EK 8 data bits, 1 stop bit, even parity
EL 8 data bits, 1 stop bit, odd parity
EM * 8 data bits, 1 stop bit, no parity
EN 8 data bits, 2 stop bits, no parity

LM520 Scanner Configuration Section 3
16 LM520 Scanner Integration & Programming Manual
Flow Control
As shown in Table 5, the LM520 scanner supports standard flow control protocols, including
XOn/XOff (software flow control) and CTS/RTS (hardware flow control). If CTS/RTS is
being used, first send the HA command before sending a new Flow Control command
(HB - HN). If the CTS and RTS lines are not used for flow control, they can be used to moni-
tor and control the scanner. The default setting is no flow control: CTS = none; RTS = low
when scanning in process and Xon/Xoff disabled. To return to this configuration send the
HA command followed by the HN command.
Table 5. Flow Control
Command Setting
HA *
No Flow Control
Xon/Xoff disabled
CTS mode = none
RTS mode = RTS low when ready to receive
HB Xon/Xoff Enabled
CTS mode = none
HC CTS mode = Low to transmit
Xon/Xoff disabled
HD CTS mode = High to transmit
Xon/Xoff disabled
HE CTS mode = Low to begin scanning
Xon/Xoff state unchanged
HF CTS mode = High tobegin scanning
Xon/Xoff state unchanged
HG RTS = Always Low
HH RTS = Always High
HI RTS = Low when scanner is ready to receive commands
HJ RTS = High when scanner is ready to receive commands
HK RTS = High when scanner has data to send
HL RTS = Low when scanner has data to send
HM RTS = High when scanning is in progress
HN * RTS = Low when scanning is in progress
NOTE
If Xon/Xoff is enabled, then RTS = low when scanning and CTS = none
If Xon/Xoff is disabled, then RTS = low when ready to scan and CTS =none
Low = Mark signal (negative voltage)
High = Space signal (positive voltage)