Postek G-2108 User manual

FCC Notice
This device complies with Part 15 of the FCC Rules. Operation is subject to the following two
conditions: (1) this device may not cause harmful interference, and (2) this device must accept any
interference received, including interference that may cause undesired operation.
This equipment may generate, use and/or radiate radio frequency energy. If not installed and used in
full accordance with this User’s Manual, interference to radio communications may occur. This
equipment complies with the limits for a Class A Information Technology Equipment pursuant to
Part 15 of the FCC Rules, which are designed to provide reasonable protection against such
interference when operated in a commercial environment. Operation of this equipment in a
residential area may also cause interference. In such case the user, at his/her expense, will be
required to correct the interference using whatever means necessary.
Trademarks
POSTEK is a registered trademark by POSTEK Electronics Co., Ltd.
ARM is a registered trademark of Advanced RISC Machines Ltd.
Microsoft, Windows are registered trademarks of Microsoft Corporation.
Copyright
© 2021 by Postek Electronics Co., Ltd. All rights reserved. Under the copyright laws, this manual
cannot be reproduced in any form without the prior written permission of POSTEK. No patent
liability is assumed, with respect to the use of the information contained herein.
Disclaimer
POSTEK barcode/RFID printers are developed and produced by Postek Electronics Co., Ltd
(hereinafter as “POSTEK”) with the adoption of direct thermal/thermal transfer printing and RFID
encoding techniques. For thermal transfer printing, matching ribbons and media are required.
Meanwhile, the wide variety of RFID chip and antenna designs make it difficult to guarantee RFID
tag’s 100% compatibility with POSTEK printers, to satisfy your printing needs, please consult with
the local reseller(s) to choose the matching consumables for POSTEK printers.
This manual has been validated and reviewed for accuracy. The instructions and descriptions it
contains are accurate for the POSTEK printer at the time of this manual’s distribution. However,
succeeding printers and manuals are subject to change without notice. POSTEK assumes no liability
for damages incurred directly or indirectly from errors, omissions or discrepancies between the
printer and this manual.
To protect your interest, and to prevent loss due to improper handling, please read the
corresponding user’s manual before operation, and don't use the printer during abnormal conditions.
In no event shall POSTEK be liable for any damage or loss caused by human misoperation,
including but not limited to loss of business profits, business interruption, loss of business
information, or other pecuniary loss.
Although this manual describes and details many issues which could possibly occur, the
manufacturer cannot warrant against unpredictable conditions during the printer’s application. For
problems such as the printer not working, missed or unclear print content, etc., POSTEK and/or its

resellers are responsible for troubleshooting (according to POSTEK Warranty Clauses). In no event
shall POSTEK or the resellers involved be liable for any direct or indirect loss, including but not
limited to loss of business profits, business interruption, loss of business information, or other
pecuniary loss.
Important Safety Instructions
•Only qualified and trained service technicians should attempt to repair the printer.
•Do not place the printer on or near a heat source.
•Be sure that the output of the power adapter is 24VDC and your power source matches the
rating listed on the power adapter. Be certain your power source is grounded.
•To avoid getting an electric shock, do not use a worn or damaged power cord. If the power cord
becomes damaged or frayed, replace it immediately.
•Do not insert anything into the ventilation slots or openings on the printer.
•The printer and power adapter should never be operated in a location where either one can get
wet. Personal injury may result.
•The printhead becomes hot while printing. To protect from damaging the printhead and risk of
personal injury, avoid touching the printhead.
•To get increased printhead longevity and higher quality printouts, always use approved labels,
tags and thermal transfer ribbons. Approved supplies can be ordered from your Postek
authorized reseller.
•Static electricity that accumulates on the surface of the human body or other surfaces can
damage or destroy the printhead or electronic components in this device. DO NOT touch the
printhead or the electronic components with bare hands.
•Place the printer on a flat, firm, solid surface.
•Never operate in a high temperature environment.
•Turn off the power when not in use for extended periods.
•Follow all recommendations and setup instructions included in this manual.

G-2108/G-3106 User’s Manual Contents
i
Contents
Preface ..........................................................................................................................1
Important Notes...........................................................................................................2
Chapter 1: Introduction..............................................................................................4
1.1 Specifications.........................................................................................................................4
1.2 Contents in the Box................................................................................................................5
Chapter 2: Setup and Use...........................................................................................6
2.1 Main Parts and Structures......................................................................................................6
2.1.1 Front View.....................................................................................................................6
2.1.2 Internal View.................................................................................................................7
2.1.3 Rear View......................................................................................................................8
2.2 Setting up the Printer..............................................................................................................9
2.2.1 Interface Connection.....................................................................................................9
2.2.2 Connecting the Printer ..................................................................................................9
2.2.3 Loading the Ribbon.....................................................................................................10
2.2.4 Loading the Media......................................................................................................14
2.2.5 Adjusting the Position of Media Sensor......................................................................16
Chapter 3: Operations and Settings ........................................................................19
3.1 Basic Operations..................................................................................................................19
3.1.1 Power Switch ..............................................................................................................19
3.1.2 The Front Panel...........................................................................................................19
3.1.3 Advanced Functions....................................................................................................21
3.1.4 Setting Operation Mode..............................................................................................22
3.1.5 Changing the Mode of Media Sensor .........................................................................25
3.2 Adjusting the Printhead Pressure .........................................................................................27
3.3 Installing Windows Driver and Label Editing Software......................................................28
Chapter 4: Maintenance ...........................................................................................29
4.1 Cleaning the Printhead.........................................................................................................29
4.2 Cleaning the Platen Roller ...................................................................................................29
4.3 Cleaning the Printer Interior ................................................................................................29
4.4 Cleaning the Sensors............................................................................................................30
Chapter 5: Troubleshooting......................................................................................31
5.1 LED Error Indications..........................................................................................................31
5.2 Miscellaneous Issues............................................................................................................32
Appendix A: Interface Specifications......................................................................33
Appendix B: ASCII Table.........................................................................................34

G-2108/G-3106 User’s Manual Preface
1
Preface
The G-2108/G-3106 Light Industrial printer is designed to provide general-purpose and
high-performance printing capabilities. Boasting multiple, user-friendly functions and high
performance, the G-2108/G-3106 printer stands out with its modern appearance and excellent
functionality. Carefully designed G-2108/G-3106 units are rugged, durable and easily operated and
maintained. The 32-bit embedded ARM CPU and high-tech system platform delivers the highest
quality possible.
This manual explains how to set up and begin using your G-2108/G-3106 printer. It also provides
detailed information on configuring your printer, basic operations, care and troubleshooting.
Please read this manual carefully before using the G-2108/G-3106 printer.
Symbol Conventions
The symbols that may be found in this document are defined as follows.
Symbol
Description
Alerts you to a medium or low risk hazard that could, if not avoided,
result in moderate or minor injury.
Alerts you to a potentially hazardous situation thatcould, if not avoided,
result in equipment damage, data loss, performance deterioration, or
unanticipated results.
Provides additional information to emphasize or supplement important points
in the main text.
Version
Version 1.2, published in August, 2021.

G-2108/G-3106 User’s Manual Important Notes
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Important Notes
Please read the following passages thoroughly before proceeding.
Printhead
The thermal printhead can be easily damaged due to its precision construction. A printhead
damaged by misuse is not covered under the terms of the warranty. To ensure longevity of the
printhead, please note the following:
•DO NOT scrape or use tools that might damage the printhead surface.
•To protect from corroding the printhead, DO NOT touch the printhead with bare hands.
•DO NOT use thermal paper or thermal transfer ribbons which contain Na, K or Cl elements.
•Keep printhead from any form of liquid or dampness.
•Only use a cotton swab dipped in anhydrous isopropyl alcohol to clean the printhead.
•Always use high-quality consumables:
➢When the printhead module is closed, pressure is placed directly onto the printhead; dirt
such as paper scraps, sand, dust and glue can scrape or damage the printhead.
➢The TPH is also easily damaged by static electricity, which may be generated by poor
quality ribbons.
•Always inspect consumables for high quality before purchasing.
The G Series printer functions under Direct Thermal or Thermal Transfer print modes. Thermal
Transfer is set as the factory default (requires ribbon for printing). However, if you need to print
on Direct Thermal materials (ribbon is not required), please contact your printer supplier or
service provider to reduce the printhead pressure. This can protect your printhead from early
performance deterioration due to direct contact with the thermal media. Any physical printhead
damage caused by direct thermal printing is not covered under warranty.
Cutter (Optional)
The printer equipped with a cutter can automatically cut the label after printing. However,
automatic cutters pose a safety hazard since the blades are very sharp. To prevent injuries and cutter
failures while using one of the many types of automatic cutters, please follow the safety and
maintenance rules listed below:
•Before using the cutter, be sure you have been trained by a qualified individual. A written
procedure covering the cutter's use is recommended.
•It is very important to choose the right cutter model for the application to ensure personal safety
and prevent damage to the cutter caused by cutting wrong types of media.
•Keep loose items such as long hair, clothing, jewelry, away from the cutter.
•Don't put anything except print media inside the cutter.
•Turn off power of printer if you notice abnormality with the cutting process and alert a
qualified technician to resolve the issue.
•Never cut a print media which exceeds the maximum operating conditions of the cutter.

G-2108/G-3106 User’s Manual Important Notes
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•Not every cutter model is designed to be able to cut through adhesive. Use only the dedicated
cutters to cut through adhesive materials. Even so, regular cleaning is required to remove the
adhesive built up on the blades over time to prevent cutter jam.
•Routine inspection and maintenance are required to be performed by a qualified technician to
keep the cutter in good working conditions.

G-2108/G-3106 User’s Manual Chapter 1: Introduction
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Chapter 1: Introduction
1.1 Specifications
Model by Resolution
203DPI
300DPI
Printing Mode
Direct Thermal & Thermal Transfer
Max Printing Speed
6ips (152.4 mm/s)
5ips (127 mm/s)
Max Printing Width
4.25″ (108 mm)
4.17″ (106 mm)
Max Printing Length
315″ (8000 mm)
157″ (4000 mm)
HEATTM Level
I
I
Memory
64 MB FLASH ROM, 16 MB SDRAM
Media
Width: 4.4″ (112 mm) max., 0.98″ (25 mm) min.
OD: 6″ (152 mm) max.
ID: 1″ (25.4 mm) min.
Media Thickness
0.003″ ~ 0.008″ (0.08 ~ 0.20 mm), including liner
Ribbon
Width: 4.3″ (110 mm) max.
Length: 984' (300 m) max.
OD: 2.75″ (70 mm) max.
ID: 1″ (25.4 mm) min.
Media Sensor
Reflective (Adjustable) / Transmissive (Two positions)
Fonts
Five built-in dot matrix ASCII fonts, user-downloadable TrueType Fonts
Barcode Types
1D Barcode: Code 39, Code 93, Code 128/subset A,B,C, Codabar,
Interleave 2 of 5, UPC A/E 2 and 5 add-on, EAN-13/8/128, UCC-128, etc.
2D Barcode: MaxiCode, PDF417, Data Matrix, QR Code, etc.
Interfaces
RS-232 Serial, 10/100 M Adaptive Ethernet, USB DEVICE 2.0
Power Adapter
Input: AC 100~240 V, 50~60 Hz
Output: DC 24 V, 2.5 A
Weight
7.72lbs (3.5 kgs)
Dimensions
W 10.2″ (259mm) x D 13.9″ (354mm) x H 8.1″(205 mm)
Operating
Environment
Temperature: 32F ~ +104F (0C ~ 40C)
Relative humidity: 5% - 85% non condensing
Storage Environment
Temperature: -40F ~ +140F (-40C ~ 60C)
Relative humidity: 5% - 85% non condensing
Optional Items
Centronics Parallel Port*
Cutter, External Label Rewinder, External Media Stand, Media Guide
Adapter
HEATTM, or Heating Equilibrium Adaptive Tuning, is a POSTEK designed and developed
cutting-edge technology that sets the benchmark for heat management in thermal printing. Printers
equipped with HEATTM have significant improvements in their printout clarity and print speed. The
HEATTM level represents the fineness of the heating uniformity with level I being the finest.
*Factory dependent.

G-2108/G-3106 User’s Manual Chapter 1: Introduction
5
1.2 Contents in the Box
Inspect the shipping carton(s) for possible shipping damage, if damage is discovered, notify the
shipping company to report the nature and extent of the damage.
Please check the items according to the Packing List. If there are any items missing, notify your
authorized reseller.

G-2108/G-3106 User’s Manual Chapter 2: Setup and Use
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Chapter 2: Setup and Use
2.1 Main Parts and Structures
2.1.1 Front View
Figure 2-1 shows the front view of the printer.
Figure 2-1 Front View
Table 2-1 Front View Description
Number
Description
1
[CANCEL/ Reset] Button
2
[FEED/Calibration] Button
3
[PAUSE/Self Test] Button
4
[READY] Indicator
5
[MEDIA] Indicator
6
[RIBBON] Indicator
7
Tear-off Bar
8
Right Cover

G-2108/G-3106 User’s Manual Chapter 2: Setup and Use
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2.1.2 Internal View
Figure 2-2 shows the detailed structure of the printer.
Figure 2-2 Internal View
Table 2-2 Internal View Description
Number
Description
1
Printhead
2
Printhead Bracket
3
Platen Roller
4
Left Mount_Ribbon supply
5
Ribbon End Sensor
6
Reflective Media Sensor
7
Transmissive Media Sensor
8
Printhead Release Lever
9
Media Guide
10
Media Guide Rod
11
Release Knob
12
Media Compartment
13
Printhead Module

G-2108/G-3106 User’s Manual Chapter 2: Setup and Use
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2.1.3 Rear View
The printer is equipped with multiple interfaces. See Figure 2-3.
Figure 2-3 Rear View
Table 2-3 Rear View Description
Number
Description
1
RS-232 Serial Port
2
USB Device Port
3
Ethernet Port
4
DC In Port
5
Centronics Parallel Port (Extensible)
6
Power Switch

G-2108/G-3106 User’s Manual Chapter 2: Setup and Use
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2.2 Setting up the Printer
2.2.1 Interface Connection
When connecting the G-2108/G-3106 printer to a computer via the USB interface cable, make sure
to utilize the same USB port used during the driver installation process. If the same USB port is not
available or not known, then please go to the printer driver’s Properties Dialogue Box, and make
sure the correct port is checked under the Ports tab.
The G-2108/G-3106 printer supports RS-232 Serial, USB Device, and 10/100 M Adaptive Ethernet
interface connections. Centronics parallel connection requires an optional Centronics Parallel
Interface Card.
To connect:
•Make sure the printer is powered OFF.
•The printer will identify the communication port automatically.
•The default values of printer port can be obtained from the self-test report. (See 3.1.3 Advanced
Functions/Obtaining Printer Configuration Information)
•Cable configurations for Serial (RS-232C) interface can be found in Appendix A: Interface
Specifications of this guide.
•Please take the following measures to reduce cable noise.
➢Restrict the length of the interface cable to less than 6’ (1.83 M) if possible.
➢Keep the interface cable separate from power cords.
2.2.2 Connecting the Printer
•Do not use the printer near liquids or corrosive chemicals.
•Using a wrong power adapter may cause damage to your printer. POSTEK assumes no
liability for any damage in such cases. The rating for the printer is 24VDC.
1. Make sure the printer is switched OFF.
2. Connect the power cord to the Power Adapter.
3. Connect the Power Adapter’s DC output plug to the DC In Port on the back of the printer.
4. Plug the power cord into a live wall outlet.

G-2108/G-3106 User’s Manual Chapter 2: Setup and Use
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2.2.3 Loading the Ribbon
•Please make sure the ribbon you are using has the ink side out.
•When using a ribbon roll with a width less than 110m, please place the ribbon roll in the
middle of the Ribbon Spindle corresponding to the symmetry symbol (→|←).
•No need to load the ribbon when printing direct thermal media.
To install the ribbon:
1. Lift the right cover and push down the Printhead Release Lever to release the Printhead Module,
see Figure 2-4.
Figure 2-4 Release the Printhead Module
2. Lift the Printhead Module to expose the Ribbon Supply compartment, see Figure 2-5.

G-2108/G-3106 User’s Manual Chapter 2: Setup and Use
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Figure 2-5 Lift the Printhead Module
3. Unwrap the ribbon package and separate the ribbon roll and the spare core.
4. Slide the ribbon roll onto one of the Ribbon Spindles and place the spare core onto the other
spindle, see Figure 2-6.
Figure 2-6 Place Ribbon Roll and Spare Core on Ribbon Spindles
5. Pull the Release Knob of the Ribbon Supply compartment outwards and place the ribbon roll in
the Ribbon Supply compartment, aligning its ends with the Left Mount and the Right Mount
which the Release Knob is attached to. Release the knob to secure the ribbon roll in the Ribbon
Supply compartment, see Figure 2-7.

G-2108/G-3106 User’s Manual Chapter 2: Setup and Use
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Figure 2-7 Load Ribbon Roll
6. Route the ribbon through the Printhead Module and wrap the end of the ribbon around the spare
core, see Figure 2-8.
Figure 2-8 Wrap Ribbon on the Core
7. Pull the Release Knob of the Ribbon Take-up compartment outwards and load the core in the
Ribbon Take-Up compartment, see Figure 2-9.
Release Knob

G-2108/G-3106 User’s Manual Chapter 2: Setup and Use
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Figure 2-9 Place the Core on Ribbon Take-up
8. Turn the Left Mount of Ribbon Take-up to ensure the ribbon is tight and smooth, see Figure
2-10.
Figure 2-10 Ribbon Roll loaded
To make sure the Ribbon End Sensor works properly, please use ribbon rolls which end with
reflective materials or transparent materials with good reflective performance.
Release Knob
Left Mount_Ribbon Take-up

G-2108/G-3106 User’s Manual Chapter 2: Setup and Use
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2.2.4 Loading the Media
The G-2108/G-3106 printer can be operated under four different modes: Standard Mode, Tear-off
Mode, Cutter Mode, and Peeler Mode.
•In Standard Mode, the printer stops and goes into standby as soon as the print job is complete.
•In Tear-off Mode, after the print job is finished, the printer will feed the label until the edge of
it aligns with the edge of the Tear-off Bar allowing easy tear off for the user.
•In Cutter Mode, the printer stops and cuts the printed label(s) (Only available on models with
cutter installed).
•In Peeler Mode, printer stops and waits for the printed and peeled off label to be taken away
before resuming the print job (Only available on models with peeler installed).
Standard Mode
To load media into the G-2108/G-3106 printer while under Standard Mode, follow the steps below:
1. Load a roll of media (labels facing up) on the Media Spindle, then slide the two Media Roll
Guides, with smooth sides facing toward the media, onto the Media Spindle from each end until
both Media Roll Guides touch the media. When placing a roll of media with a 3″ ID core, please
slide the two Core Adapters onto the Media Spindle first, as shown in Figure 2-11.
Figure 2-11 Place Media Roll on Media Spindle
2. Place the entire unit into the media compartment in the printer.
3. Position the media roll in the middle of the Spindle, using the ruler on the Media Spindle for
alignment.
4. Thread the media under the Media Guide Rod and Transmissive Media Sensor, as shown in
Figure 2-12.
Media Roll
Media Roll Adaptors
Media Spindle
Media Roll Guide
Media Roll
Module correctly
fitted with Spindle
and Guides

G-2108/G-3106 User’s Manual Chapter 2: Setup and Use
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Figure 2-12 Load the Media
5. Slide the Media Guide to the edge of the media, making sure that the media remains flat and is
placed in the middle of the Tear-off Bar. This can be checked with the ruler on the Tear-off
Bar.
6. Press the Printhead Module downward until you hear a “click”, as shown in Figure 2-13.
Figure 2-13 Press Down to Lock the Printhead Module
7. Turn on the printer, press and hold the [FEED/Calibration] button (hold for around 4 seconds),
then the printer will automatically feed labels and the media calibration is done.
Media Guide
Media Guide Rod

G-2108/G-3106 User’s Manual Chapter 2: Setup and Use
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Calibration must be made when media is loaded to the printer for the first time, or when there
is a change to a different type of media.
2.2.5 Adjusting the Position of Media Sensor
1. Lift the right cover.
2. Push down the Printhead Release Lever to release the Printhead Module.
3. To adjust the position of the Reflective Sensor: Lift the Printhead Module to expose the Media
Sensor cover, remove the Media Sensor cover and slide the Media Sensor to the appropriate
position, then replace the media sensor cover.
4. To adjust the position of the Transmissive Sensor: Flip the Toggle Switch to choose center or
right position according to the media type, see Figure 2-14.
Figure 2-14 Adjust the Media Sensor Position
•Black ribbon is required when use Reflective Sensor, or the Media Out signal may not be
detected.
•Technically, the Transmissive Sensor is designed to detect a gap, hole or notch between labels,
the Reflective Sensor is for detecting black marks. However, in many cases, the Reflective
Sensor also can be used to detect gap, hole or notch. When choose Reflective Sensor to detect
Slide-Reflective Sensor
Toggle Switch-Transmissive Sensor