Digi Digi Connect EM DC-EM02T-JT Application guide

Digi Connect EM™ and Digi Connect
Wi-EM™
Hardware Reference

Revision history—90000632
Revision Date Description
EMarch, 2005 Added Japan certification, updated desktop antenna and
sensitivity information and improved illustrations.
F August, 2005 Added Ethernet pinouts and product weights, and updated
antenna specifications.
G Ocober, 2006 Updated dimension drawings and Tyco antenna
specifications.
H January, 2010 Corrected part numbers and revised schematics.
J August, 2017 Updated branding and modified regulatory and certification
information as required by RED (Radio Equipment Directive).
Trademarks and copyright
Digi, Digi International, and the Digi logo are trademarks or registered trademarks in the United
States and other countries worldwide. All other trademarks mentioned in this document are the
property of their respective owners.
© 2017 Digi International Inc. All rights reserved.
Disclaimers
Information in this document is subject to change without notice and does not represent a
commitment on the part of Digi International. Digi provides this document “as is,” without warranty of
any kind, expressed or implied, including, but not limited to, the implied warranties of fitness or
merchantability for a particular purpose. Digi may make improvements and/or changes in this manual
or in the product(s) and/or the program(s) described in this manual at any time.
Warranty
To view product warranty information, go to the following website:
www.digi.com/howtobuy/terms
Send comments
Documentation feedback: To provide feedback on this document, send your comments to
[e-mail].
Customer support
Digi Technical Support: Digi offers multiple technical support plans and service packages to help our
customers get the most out of their Digi product. For information on Technical Support plans and
pricing, contact us at +1 952.912.3444 or visit us at www.digi.com/support.
Digi Connect EM and Digi Connect Wi-EM Hardware Reference 2

Contents
About this guide
Scope of the reference manual 6
Kits contents 6
About the integration kit 6
About the development kit 7
Related documentation 7
About the Embedded module
Digi Connect EM and Digi Connect Wi-EM overview 8
Types of modules 8
Choosing a module for your product 8
Digi Connect Wi-EM antenna 10
Connectors: power and serial interface 11
Power and serial interface 11
Connectors: Ethernet interface 12
Connectors: antenna 12
Wi-EM antenna connectors 12
Reset switch 13
Reset switch location 13
Module LEDs 14
Digi Connect EM pin header locations (top view) 15
Ethernet pin header, P13 15
About the development board
Overview 16
Basic description 16
Ports 17
Serial port 1 (P1) and serial port 2 (P2) 17
Ethernet port (P12) 17
GPIO port (P3) 18
Connectors and blocks 20
JTAG debugger connector (P4) 20
SPI Connector (P11) 20
SPI jumper block 21
Logic signal analyzer header (P6) 22
Main connector (P8) 23
Power jack (P17) 24
Switches 25
Digi Connect EM and Digi Connect Wi-EM Hardware Reference 3

Digi Connect EM and Digi Connect Wi-EM Hardware Reference 4
Reset switch (SW5) 25
Serial/GPIO switch bank 3 (SW3) and switch bank 4 (SW4) 25
GPIO switch bank 1 (SW1) and 2 (SW2) 26
Development board LEDs 27
Test points 29
Programming considerations
GPIO 30
GPIO registers 30
GPIO pin use 31
Embedded Module LEDs 32
About embedded module LEDs 33
Embedded Module Reset 33
Flash 34
Specifications
Network interfaces 35
Digi Connect Wi-EM embedded module 35
Digi Connect EM embedded module 35
Serial interface 35
Data rates (bps) 35
Flow control options 36
Environmental 36
DC characteristics 36
Mechanical 37
Layouts and dimensions 39
Digi Connect Wi-EM (w/LED array) 40
Digi Connect Wi-EM (w/LED pin headers) 42
Digi Connect EM (w/RJ-45 and LED array) 44
Digi Connect EM (with Ethernet and LED pin headers) 46
Recommended PCB layouts 48
Digi Connect Wi-EM (w/LED array) 48
Digi Connect Wi-EM (w/LED pin headers) 49
Digi Connect EM (w/RJ-45 and LED array) 50
Digi Connect EM (with Ethernet and LED pin headers) 51
Antenna information 52
Antenna strength 52
Antenna specifications for North America 53
Dipole antenna dimensions 54
Desktop antenna dimensions 55
PCB mount antenna dimensions 56
RF Exposure statement 56
Safety statements 56
Regulatory information
United States (FCC) 59
OEM labeling requirements 59
FCC notices 59
RF Exposure statement 60
Modifications (FCC 15.21) 60

Digi Connect EM and Digi Connect Wi-EM Hardware Reference 5
Europe 60
Declarations of conformity 61
International EMC standards 61
Sample application: TTLsignalstoEIA-232

About this guide
Scope of the reference manual
The purpose of this document is to enable developers to integrate the Digi Connect EM or Digi
Connect Wi-EM modules into other devices. Graphics illustrate the placement and dimensions of
components for both the modules and the development board. Information for both the Digi Connect
EM and the Digi Connect Wi-EM are identical unless called out specifically in the manual.
Kits contents
This manual is intended for customers who use either the Digi Connect EM/Digi Connect Wi-EM
Integration Kit or the Digi Connect EM/Digi Connect Wi-EM Development Kit, which are described
below.
About the integration kit

The integration kit is the ideal platform for product evaluation, rapid prototyping, and integration of
the Digi Connect EM or Digi Connect Wi-EM embedded device server. Targeted specifically at
customers who want to take advantage of the Digi Connect EM or Digi Connect Wi-EM embedded
device server with Digi plug-and-play firmware functionality, both products enable integration of the
Digi Connect EM or Digi Connect Wi-EM embedded module without any extensive embedded software
development with all the additional flexibility and benefits of web user interface customization and
application specific java applets. Included in the Digi Connect EM or Digi Connect Wi-EM Integration
Kits are the following:
nComplete development board with EIA-232 serial ports, signal status indicators, logic analyzer
connectors, test points, and a self-contained GPIO test bed.
nCables
lDB-9 to DB-9 Crossover cable
lDB-9 to DB-9 Modem cable
lRJ-45 Ethernet Crossover cable
nLoopback plug
nPower supply
nWrist strap (for grounding)
Digi Connect EM and Digi Connect Wi-EM Hardware Reference 6

About this guide Related documentation
Digi Connect EM and Digi Connect Wi-EM Hardware Reference 7
nDigi Connect CD
lSample code
lTools and utilities with source code and libraries
lMicrosoft Windows RealPort drivers
nFull software and hardware documentation
About the development kit

The Digi Connect EM or Digi Connect Wi-EM Development Kit is an easy-to-use and royalty-free
development platform that significantly reduces traditional design risk and accelerates the overall
software development process. Both kits deliver the integrated building blocks to quickly and cost
effectively create your own custom firmware for a Digi Connect EM or Digi Connect Wi-EM based high-
performance networking solution that fits the specific requirements of your application.
Based on the NET+Works family of platform solutions, the Digi Connect EM or Digi Connect Wi-EM
development kits enable you to integrate custom network connectivity into your products quickly by
providing a full suite of development tools inlcuding:
nDevelopment board
nCables
nPower supply
nHardware debugger
nComplete set of networking protocols and applications software
Related documentation
See the NS 7520 Hardware Reference for information on the NS 7520 chip.

About the Embedded module
Digi Connect EM and Digi Connect Wi-EM overview
The embedded modules are part of Digi Connect family of device servers that provide simple, reliable
and cost-effective network connections for serial devices. They provide fully transparent serial device
connectivity over industry-standard Ethernet connections and allow both equipment manufacturers
and systems integrators to network-enable products at a fraction of the time and cost required to
develop a custom solution. It is a highly flexible and compact single component solution with a robust
on-board TCP/IP stack and 10/100 Base-T Ethernet or wireless support. Features include the
following:
n32-bit NS7520 processor with ARM7TDMI core
n4MB Flash and 8MB RAM on board
n2 High Speed Serial Ports
nSPI Master Mode Interface
n9 General Purpose Input/Output Port Options
nAvailable with Digi plug-and-play firmware
nNetSilicon NET+Works platform for embedded software development
From medical systems to building control and industrial automation, in virtually any application where
embedded serial connectivity over Ethernet is needed, the embedded module is the ideal choice,
delivering high-performance functionality.
Cautions
To guard against damage to the module due to electrostatic discharge (ESD), do not remove it from
its protective packaging until you have been properly grounded. To ground yourself, put the wrist
strap on (included in the package) and then attach the clip to a metal surface.
nInput voltage for the module is 3.3 VDC.
Types of modules
The following describes the three types of Digi Connect EM and three types of Digi Connect Wi-EM
modules:
Choosing a module for your product
Although any of the embedded modules can be designed into your product, a JTAG header would
typically be used only for debugging during the development process. The Digi Connect EM module
Digi Connect EM and Digi Connect Wi-EM Hardware Reference 8

About the Embedded module Types of modules
Digi Connect EM and Digi Connect Wi-EM Hardware Reference 9
part number DC-EM-02T-S or DC-EM-02T-C is appropriate when its integrated LEDs and RJ-45
Ethernet connectors are accessible and visible to the end-users of your product. The Digi Connect EM
module part number DC-EM-02T-NC or DC-EM-02T-JT is the right choice when you want more
control over RJ-45 Ethernet connector and LED locations or when you will provide custom connectors
or indicators.
The Digi Connect Wi-EM module part number DC-WEM-02T-C or DC-WEM-02T-S is appropriate
when its integrated LEDs are accessible and visible to the end-users of your product. The Digi Connect
Wi-EM module part number DC-WEM-02T-JT or DC-WEM-02T-NC is the right choice when you want
more control over LED locations or when you will provide custom connectors or indicators.
Please refer to the Digi website www.digi.com for part number and ordering information for the
modules.
Digi Connect EM Modules
Model Description Figure
DC-EM-
02T-JT
nUsed for development purposes only
nJTAG interface
nPin headers for Ethernet and LED functionality.

DC-EM-
02T-NC
nNo JTAG interface
nPin headers for Ethernet and LED functionality
nOrdered independently of development kit for
use in your implementation
DC-EM-
02T-S
DC-EM-
02T-C

nNo JTAG interface
nRJ-45 Ethernet connector and LED array
nOrdered independently of either the
development or integration kit for use in your
implementation.



About the Embedded module Types of modules
Digi Connect EM and Digi Connect Wi-EM Hardware Reference 10
Digi Connect Wi-EM Modules
Model Description Figure
DC-WEM-
02T-JT
nUsed for development purposes only
nJTAG interface
nPin headers LED functionality
nDual RP-SMA Antenna Connector.

DC-WEM-
02T-NC
nNo JTAG interface
nPin headers LED functionality
nDual RP-SMA Antenna Connector
nOrdered independently of development kit for
use in your implementation

DC-WEM-
02T-C
DC-WEM-
02T-S
nNo JTAG interface
nLED array
nDual RP-SMA Antenna Connector
nOrdered independently of either development
or integration kit for use in your
implementation.

Note:
nS: No JTAG, w/ LED array, w/RJ-45/antenna connectors, for use with Digi Firmware
nC: No JTAG, w/LED array, RJ-45 / antenna connectors, for use with Custom Firmware
nNC: No JTAG, w/LED pin header, w/o RJ-45 connector (for Digi Connect EM), w/antenna
connectors (for Digi Connect Wi-EM), for use with custom firmware (not shown)
nJT: w/ JTAG, w/pin header, w/o RJ-45 connector (for Digi Connect EM), w/ antenna connectors
(for Digi Connect Wi-EM), for use with custom firmware development
Digi Connect Wi-EM antenna
The Digi Connect Wi-EM is available with dual-diversity antenna connectors. The right antenna (P2) is
always used for transmit and receive. The left antenna is receive only. The antenna will choose the
best signal (pin vs. socket). The Digi Connect Wi-EM always has two antenna connectors but using the
second antenna is optional.
The antenna are connected to the module with reverse polarity SMA connectors (sub-miniature size
A). The antenna fit the connectors on the module only one way to ensure a proper connection. The

About the Embedded module Connectors: power and serial interface
Digi Connect EM and Digi Connect Wi-EM Hardware Reference 11
antenna function best when placed perpendicular to each other (one straight, the other up or down)
to prevent interference from each other.
Another option for both signal reception and design flexibility is to use an antenna extension cord (Digi
part number DC-ANT-E-24DP) to separate the antenna from the module. This allows the module to fit
inside your product but the antenna to be placed outside the device.
Connectors: power and serial interface
This single 12-pin, serial interface port (labeled P4 for Digi Connect EM and P5 for Digi Connect Wi-EM)
supports 2 TTL serial interfaces, data rates up to 230 Kbps and full-modem control (on port 1). See the
figure for help locating pins and the table for pin assignments.
Power and serial interface
Power and Serial Interface Pin Assignments
Pin Signal Name Description and Notes
1 VCC +3.3 VDC (input only)
2 GND Reference Ground for input power
3 RXD/GPIO-7 Port 1 RXD (input)/GPIO-7
4 TXD/GPIO-6 Port 1 TXD (output)/GPIO-6
5 RTS/GPIO-4/SPI_CLK Port 1 RTS/GPIO-4/SPI clock
6 DTR/GPIO-5 Port 1 DTR (output)/GPIO-5
7 CTS/GPIO-2 Port 1 CTS (input)/GPIO-2
8 DCD/GPIO-1/SPI_EN Port 1 DCD (input)/GPIO-1/SPI enable

About the Embedded module Connectors: Ethernet interface
Digi Connect EM and Digi Connect Wi-EM Hardware Reference 12
Power and Serial Interface Pin Assignments
Pin Signal Name Description and Notes
9 DSR/GPIO-3 Port 1 DSR (input)/GPIO-3
10 /RST Reset (input)
11 RXD/GPIO-9 Port 2 RXD (input)/GPIO-9
12 TXD/GPIO-8 Port 2 TXD (output)/GPIO-8
Connectors: Ethernet interface
The following table shows the pinout of the RJ-45 connector.
RJ-45 Ethernet interface
Pin # 1 2 3 4 5 6 7 8
Signal TXD+
(transmit
data)
TXD-
(transmit
data)
RXD+
(receive
data)
Not used Not used RXD-
(receive
data)
Not used

Not used

For a diagram of the Digi Connect Ethernet pin header location and assignments see Digi Connect EM
pin header locations (top view).
Connectors: antenna
The Digi Connect Wi-EM has 2 RP-SMA antenna connectors labeled P2 and P3. P2 is only used to
transmit, while both P2 and P3 are used to recieve.
Wi-EM antenna connectors
.

About the Embedded module Reset switch
Digi Connect EM and Digi Connect Wi-EM Hardware Reference 13
CAUTION! This Part 15 radio device operates on a non-interface basis with other
devices operating at this frequency when using the antenna listed in the Antenna
Specification table. Any changes or modification to the product not expressly approved
by Digi International could void the user's authority to operate the device.
The antenna is connected to the module with a reverse polarity SMA connector (sub-miniature size A).
The antenna only fits on the module one way to ensure a proper connection. Another option for both
signal reception and design flexibility is to use an antenna extension cord (Digi part number DC-ANT-E-
24DP) to separate the antenna from the module. This allows the module to fit inside your product but
the antenna to be placed outside the device.
Antenna description
Type Desktop Dipole 30 cm
antenna extension cord
Part number DC-ANT-24DT DC-ANT-E-24DP
Gain 1.8 dBi -.5dB
Reset switch
The behavior of the reset switch is determined by software, which means that it has a predefined
behavior in the integration kit. In the development kit, its behavior is determined by your
implementation. See the following table for details.
Reset switch behavior
Kit Behavior
Integration The reset switch does one of the following:
nIf pressed and released immediately, the device is rebooted.
nIf pressed and held down (for about 20 seconds) during power-up, the device
is rebooted and restored to the default configuration.
Development nThe behavior of the switch is user-defined.
See Embedded Module Reset for more information.
Reset switch location
The reset switch is in same location for both wired and wireless modules.

About the Embedded module Module LEDs
Digi Connect EM and Digi Connect Wi-EM Hardware Reference 14
Module LEDs
The modules provide two hardware options for LEDs, with or without on board LED array. The
integration kit provides predefined LED behavior. With the development kit, some LED behavior can be
determined by your implementation. See the following table for more information.
LED behaviors
LED
Pin
header
EM
Integration kit
Digi Connect EM
Integration
kit
Digi
Connect
Wi-EM
Development
kit
Top left
(green)
1 (+)
3(-)
Serial port activity:
Off - the serial channel is idle.
Blinking - serial data is transmitted or received.
This LED is
software
programmable
Top right
(green)
5 (+)
7 (-)
Network link status:
Off - no link has been detected.
On - a link has been detected.
Network
link status:
On - unit is
associated
with an
access
point
Blinking
slowly - unit
is in ad hoc
mode
Blinking
quickly -
unit is
scanning
for a
network
Same as
Integration Kit
(Network link
status)
Bottom
left (red)
2 (+)
4 (-)
Diagnostics:
Blinking 1-1-1 - starting the operating system.
Blinking 1-5-1 - configuration has been returned to
factory defaults.
Note If other blinking patterns occur, contact Digi
Technical Support.
This LED is
software
programmable
Bottom
right
(yellow)
6 (+)
8 (-)
Blinking - network data is transmitted or received This LED is
software
programmable

About the Embedded module Module LEDs
Digi Connect EM and Digi Connect Wi-EM Hardware Reference 15
Digi Connect EM pin header locations (top view)
Ethernet pin header, P13
The pins in the Ethernet header are configured as shown:
Pin Signal
1 Ethernet transmit +
2 Ethernet transmit -
3 Ethernet receive +
4 Ethernet receive -
LED pin header
LED pins and pin header configuration are described in the LED behaviors table.

About the development board
Overview
This chapter provides information on the development board, a hardware platform from which you
can determine how to integrate the embedded module into your design. For additional information,
see the schematic and mechanical drawings. If you have installed the development kit or integration
kit, you can access the schematic from the Start menu.
Basic description
The development board can be used by both module feature sets with the Integration Kit or the
Development Kit.The following graphic is a layout of the development board.

Digi Connect EM and Digi Connect Wi-EM Hardware Reference 16

Ports
The development board provides the following ports:
nSerial Port 1 (P1) and Serial Port 2 (P2)
nEthernet Port (P12)
nGPIO Port (P3)
Serial port 1 (P1) and serial port 2 (P2)
Serial port 1 and port 2 are DB-9 male connectors labeled P1 and P2. Use the following figure and
table for pin orientation and pin assignment information.
Serial port pin orientation

Serial pin assignment
Por
t
Signal
pin 1
Signa
l
pin 2
Signa
l
pin 3
Signal
pin 4
Signa
l
pin 5
Signal
pin 6
Signal
pin 7
Signal
pin 8
Signal
pin 9
1 DCD RXD TXD DTR GND DSR RTS CTS Not
connecte
d
2 Not
connecte
d
RXD TXD Not
connecte
d
GND Not
connecte
d
Not
connecte
d
Not
connecte
d
Not
connecte
d
Ethernet port (P12)
The Ethernet port of the Digi Connect EM embedded module (labeled P12) is an 8-pin
RJ-45 jack meeting the requirements of ISO 8877 for 10/100Base-T. When two descriptions are shown
for a pin, the second is for use with 802.3af powered Ethernet.
Digi Connect EM and Digi Connect Wi-EM Hardware Reference 17

About the development board Ports
Digi Connect EM and Digi Connect Wi-EM Hardware Reference 18
Ethernet pin assignments
Pin Signal name Figure RJ-45 (P12)
1 TXD+ (transmit data) 


2 TXD- (transmit data)
3 RXD+ (receive data)
4 Not used / power (+)
5 Not used / power (+)
6 RXD- (receive data)
7 Not used / power (-)
8 Not used / power (-)
For additional information about the 802.3af standard, refer to the corresponding IEEE specification.
Note The development board provides a reference design of a POE (Power Over Ethernet) power
supply. A schematic for this reference design is installed by the setup program on the CD.
GPIO port (P3)
The GPIO port is a 10-pin male right-angle connector (labeled P3). See the following figure and table
for pin orientation and pin assignments.
GPIO port pin orientation

GPIO port pin assignments
Pin Signal name
1 GND
2 GPIO-9
3 GPIO-8
4 GPIO-7
5 GPIO-6
6 GPIO-5

About the development board Ports
Digi Connect EM and Digi Connect Wi-EM Hardware Reference 19
GPIO port pin assignments
Pin Signal name
7 GPIO-4
8 GPIO-3
9 GPIO-2
10 GPIO-1

About the development board Connectors and blocks
Digi Connect EM and Digi Connect Wi-EM Hardware Reference 20
Connectors and blocks
The development board provides the following connectors and blocks:
nJTAG debugger connector (P4)
nSPI Connector (P11) and SPI jumper block
nLogic signal analyzer header (P6)
nMain connector (P8)
JTAG debugger connector (P4)
This 14-pin male vertical header labeled P4 mates with a JTAG debugger plug (for example, a
Macraigor Raven). It is used with the development kit only. See the following figure and table for pin
orientation and assignments.
JTAG debugger connector pin orientation


JTAG debugger connector pin assignments

Pin
1
Pin
2
Pin
3
Pin
4
Pin
5
Pin
6
Pin
7
Pin
8
Pin
9
Pin
10
Pin
11
Pin
12
Pin
13
Pin
14
Signal VCC+ GND /TRST GND TDI GND TMS GND TCK GND TDO /SRST VCC+ GND
SPI Connector (P11)
This connector is used for a Serial Peripheral Interface (SPI) connection. When enabled, signals are
disconnected from serial port 1 and GPIO connectors. See the following figure and table for pin
orientation and pin assignments.