RTscan RT208 Quick setup guide

RT208 Integration Guide
RT208
OEM Scan Engine
Integration Guide

RT208 Integration Guide
Table of Contents
Chapter 1 Introduction....................................................................................................................................... 1
Overview ....................................................................................................................................................... 1
Illumination .................................................................................................................................................... 1
Aimer ............................................................................................................................................................. 1
Chapter 2 Installation......................................................................................................................................... 2
General Requirements.................................................................................................................................. 2
ESD........................................................................................................................................................ 2
Dust and Dirt.......................................................................................................................................... 2
Thermal Considerations......................................................................................................................... 3
Installation Orientation........................................................................................................................... 3
Optics ............................................................................................................................................................ 4
Window Placement ................................................................................................................................ 4
Window Material and Color ................................................................................................................... 4
Scratch Resistance and Coating ........................................................................................................... 5
Window Size .......................................................................................................................................... 5
Ambient Light......................................................................................................................................... 6
Eye Safety.............................................................................................................................................. 6
Mounting........................................................................................................................................................ 7
Front View (unit: mm) ............................................................................................................................ 7
Side View (unit: mm).............................................................................................................................. 7
Top View (unit: mm)............................................................................................................................... 8
Chapter 3 Electrical Specifications .................................................................................................................. 9
Power Supply ................................................................................................................................................ 9
Ripple Noise........................................................................................................................................... 9
DC Characteristics ...................................................................................................................................... 10
Operating Voltage................................................................................................................................ 10
Operating Current ................................................................................................................................ 10

RT208 Integration Guide
Chapter 4 Interfaces......................................................................................................................................... 11
Host Interface Connector............................................................................................................................ 11
Dimensions of the Host Interface Connector (unit: mm) ..................................................................... 12
FFC Cable (unit: mm) .......................................................................................................................... 13
Communication Interfaces .......................................................................................................................... 14
Control Interface.......................................................................................................................................... 15
Reset.................................................................................................................................................... 15
Trigger.................................................................................................................................................. 15
Beeper ................................................................................................................................................. 16
Good Read LED .................................................................................................................................. 17
Chapter 5 Development Tools ........................................................................................................................ 18
EVK ............................................................................................................................................................. 18

1
RT208 Integration Guide
Chapter 1 Introduction
Overview
TM
The RT208 supports all mainstream 1D as well as PDF417, QR Code (QR1, QR2, Micro QR), Chinese
Sensible Code, Data Matrix and GS1-DataBarTM(RSS) (Limited/ Stacked/ Expanded versions).
TM
Illumination
The RT208 has two red LEDs for supplementary lighting. The illumination can be programmed On or Off.
The RT208 uses red LEDs for illumination, so the engine shows better reading performance on barcodes
printed in non-red colors. For applications involving red barcodes, it is advised to turn off the engine’s
illumination and use non-red supplementary lighting (such as green) instead. The user can conduct some
tests to determine the proper wavelengths to be used.
Aimer
The RT208 contains a laser aimer that produces a crosshair aiming pattern to help the user to easily
position the target barcode within the engine’s field of view to increase scan efficiency. The aiming pattern
can be turned On or Off. It is advisable to turn it on when scanning barcodes.

2
RT208 Integration Guide
Chapter 2 Installation
General Requirements
ESD
ESD protection has been taken into account when designing the RT208 and the engine is shipped in ESD
safe packaging. Always exercise care when handling the engine outside its package. Be sure grounding
wrist straps and properly grounded work areas are used.
Note: The RT208’s laser diode (circled in the figure below) is ESD sensitive and rated Class 1A Human
Body Model (HBM) 270V, thus ESD protection measures, such as the ones mentioned above, must be
taken when handling or installing the RT208 to avoid damage to the laser diode.
Dust and Dirt
The RT208 must be sufficiently enclosed to prevent dust particles from gathering on the lens, circuit
boards and LEDs. Dust and other contaminants will eventually degrade the engine’s performance.

3
RT208 Integration Guide
Thermal Considerations
Electronic components in the RT208 will generate heat during the course of their operation. Operating the
RT208 continuously for an extended period may cause temperatures to rise on CIS and decoder chip. The
following precautions should be taken into consideration when integrating the RT208.
Reserve sufficient space for good air circulation in the design.
Avoid wrapping the RT208 with thermal insulation materials such as rubber.
Installation Orientation
There are two threaded mounting holes in the bottom of the RT208 for fastening the engine to a mounting
surface with machine screws. The following figure illustrates a front view of the RT208 after correct
installation.
Up

4
RT208 Integration Guide
Optics
Window Placement
The window should be positioned properly to let the illumination and aiming beams pass through as much
as possible and no reflections back into the engine (reflections can degrade the reading performance).
The window should be mounted close to the front of the engine (parallel). The maximum distance is
measured from the front of the engine housing to the furthest surface of the window. Avoid unwanted
reflections and use thin material for window so as to reach better reading performance. As shown in the
figure below, the distance from the front of the engine housing to the furthest surface of the window should
not exceed 3mm and the distance from the front of the engine housing to the nearest surface of the
window should not exceed 2mm.
If the window is required to be in a tilted position, the above distance requirements should be met and tilt
angle should ensure no reflections back into the lens.
Window Material and Color
CIS’s responsiveness (mainly to wavelengths of red light）should be taken into consideration when
choosing window material and color, in order to achieve the possible highest spectral transmission, lowest
haze level and homogeneous refractive index. It is suggested to use PMMA or optical glass with spectral
transmittance of red light over 90% and haze less than 1%. Whether to use an anti-reflection coating or
not depends on the material and application needs.

5
RT208 Integration Guide
Scratch Resistance and Coating
Scratch on the window can greatly reduce the performance of the RT208. It is suggested to use abrasion
resistant window material or coating.
Window Size
The window must not block the field of view and should be sized to accommodate the aiming and
illumination envelopes shown below.
Horizontal:

6
RT208 Integration Guide
Vertical:
Ambient Light
The RT208 shows better performance with ambient light and it is well able to handle the flicker in
fluorescent lights using 50-60Hz AC power. However, high-frequency pulsed light can result in
performance degradation.
Eye Safety
The RT208 uses red LEDs to create illumination beam. The LEDs are bright, but testing has been done to
demonstrate that the engine is safe for its intended application under normal usage conditions. However,
the user should avoid looking into the beam.
The RT208 uses a laser diode to form a bright, intuitive aiming aid. It is hazardous to stare into the laser
beam.

7
RT208 Integration Guide
Mounting
The illustrations below show the mechanical mounting dimensions for the RT208. The structural design
should leave some space between components.
Front View (unit: mm)
Side View (unit: mm)

8
RT208 Integration Guide
Top View (unit: mm)
Mounting Hole M1.6 2.0mm MAX

9
RT208 Integration Guide
Chapter 3 Electrical Specifications
Power Supply
Do not power up the RT208 until it is properly connected. Be sure the power is cut off before connecting a
flexible cable to or disconnecting a flexible cable from the host interface connector. Hot-plugging could
damage the engine.
Unstable power supply or sharp voltage drops or unreasonably short interval between power-ons may
lead to unstable performance of the engine. Do not resupply the power immediately after cutting it off. The
minimum interval must exceed 2 seconds.
Ripple Noise
Image sensor and decoder chip are directly fed by the input power of RT208. To ensure the image quality,
a power supply with low ripple noise is needed.
Acceptable ripple range (peak-to-peak) : ≤50mV (≤30mV recommended).

10
RT208 Integration Guide
DC Characteristics
Operating Voltage
Ta=25℃
Parameter
Description
Minimum
Typical
Maximum
Unit
VDD
Voltage Drain Drain
3.0
3.3
3.6
V
VIH
High Level Input Voltage
VDD-0.5
-
-
V
VIL
Low Level Input Voltage
-
-
0.5
V
VOH
High Level Output Voltage
VDD-0.3
-
-
V
VOL
Low Level Output Voltage
-
-
0.3
V
Operating Current
Ta=25℃，VDD=3.3V
Operating Current
Standby Current
Sleep Current
142mA (typical)
204mA (max.)
10.2mA
<100uA

11
RT208 Integration Guide
Chapter 4 Interfaces
Host Interface Connector
The following table lists the pin functions of the 12-pin host interface connector of the RT208.
PIN#
Signal Name
I/O
Function
1
NC
-
Not connected.
2
VDD
-
3.3V power supply.
3
GND
-
Power-supply ground.
4
RX
I
TTL level 232 receive data.
5
TX
O
TTL level 232 transmit data.
6
USB_D-
I/O
USB_D- differential data signal. (optional)
7
USB_D+
I/O
USB_D+ differential data signal. (optional)
8
NC
-
Not connected.
9
Buzz
O
Beeper output. For the information of beeper driver circuit, see the
Beeper section in this chapter.
10
LED
O
Good Read LED output. For the information of LED driver circuit,
see the Good Read LED section.
11
Reset
I
Reset signal input: Driving this pin low for 100us-500us resets the
engine.
12
nTrig
I
Trigger signal input: Driving this pin low for at least 10ms causes
the RT208 to start a scan and decode session.

12
RT208 Integration Guide
Dimensions of the Host Interface Connector (unit: mm)
The RT208 uses a 12-pin FPC ZIF socket (bottom contact, model: 10051922-1210EHLF) manufactured
by FCI. The socket can be connected to a host device with a FFC cable.

13
RT208 Integration Guide
FFC Cable (unit: mm)
A 12-pin FFC cable can be used to connect the RT208 to a host device. The cable design must be
consistent with the specifications shown below. Use reinforcement material for the connectors on the
cable and reduce cable impedance for reliable connection and stable performance.

14
RT208 Integration Guide
Communication Interfaces
The RT208 can communicate with the host device via its TTL-232 interface. This interface is applicable to
most system architectures. For those requiring RS-232, a TTL-232 to RS-232 conversion circuit is
needed.
The RT208’s TTL-232 interface supports baud rates from 1200bps to 115200bps; it does not support
hardware flow control. Its default settings are 9600bps, 8 data bits, no parity check and 1 stop bit.
Besides, the RT208 can also communicate with the host device via its USB interface (optional).
1. USB HID-KBW: Based on USB connection, the engine’s transmission is simulated as USB keyboard
input. It works on a Plug and Play basis and no driver is required.
2. USB COM Port Emulation: The USB interface on the host device is emulated as a serial port with the
same data transmission and configuration as a real serial port. A driver is required.
3. USB HID-POS: It is based on HID with no need for custom driver and is way more efficient in
communication than keyboard emulation and traditional RS-232 interface.

15
RT208 Integration Guide
Control Interface
Reset
Driving the Reset pin (PIN 11) on the host interface connector low for 100us-500us can reset the RT208.
However, do not reset the engine at unreasonably short intervals. The minimum interval between resets
must exceed 2 seconds.
Trigger
Driving the nTrig pin (PIN 12) on the host interface connector low for over 10ms causes the RT208 to start
a scan and decode session. If barcode is decoded, the RT208 waits for the voltage at the nTrig pin to turn
high (or the trigger to be released) after sending the data to the Host. If the trigger is released during a
scan attempt, the RT208 immediately stops decoding.
Next decode session does not happen until the RT208 receives active trigger signal (by driving the nTrig
pin low) again.
As a decode session involves image capture, barcode decoding and other steps, it is suggested that the
minimum interval between triggers should exceed 50ms.
The following trigger circuit is provided for reference.
B3F-4000S1
2 3
1 4
5 6
C3
100pF
CBW1608/60R
L1
C4
100pF
nTrig
R15
10K
VDD

16
RT208 Integration Guide
Beeper
The RT208 provides a pin (Buzz, PIN 9) on the host interface connector that provides a PWM output to an
external driver circuit for generating audible feedback to the user to indicate statuses like power up or
good read. The PWM output is not strong enough to drive a beeper, thus a beeper driver circuit is needed.
The following beeper driver circuit is provided for reference.
2N3904
Q8
AS903Q
LS1
1
2
R5
10R
R6 1K
R7
10K
VDD
BUZZ
BAT760
D2

17
RT208 Integration Guide
Good Read LED
The RT208 provides a pin (LED, PIN 10) on the host interface connector that can be used by an external
driver circuit to drive an LED to indicate a Good Read status. When a good read occurs, the LED pin
produces a high level output for about 300ms, and then the signal is back to a low level. This Good Read
LED output is not strong enough to drive an LED, so an LED driver circuit is needed.
The following Good Read LED driver circuit is provided for reference.
2N3904
Q8
R1 1K
LED
R3
1k
LED
D3
R2
10K
VDD