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B&B Electronics Mfg Co Inc – 707 Dayton Rd - PO Box 1040 - Ottawa IL 61350 - Ph 815-433-5100 - Fax 815-433-5104 – www.bb-elec.com
VLINX Models ESP901 and ESP902 Ethernet Serial Servers provide
Ethernet to Serial connections for RS-232, RS-422 or RS-485 devices.
The ESP901 features a single serial port and the ESP902 features two
serial ports. The serial ports can be accessed over a LAN/WAN using
Direct IP Mode, Virtual COM Port, or Paired Mode connections. The
10/100 Mbps Ethernet connection auto-selects 10BaseT or 100BaseTX
and indicates the type of connection with a bi-color link light.
Figure 1. VLINX ESP901 and ESP902 Ethernet Serial Servers
• TCP or UDP Client or Server operation - configurable
• Software Support - Windows 98/ME/2000/2003/XP/NT 4.0 and
Vista
• Firmware Upload for future revisions/upgrades
• Configuration of Ethernet and serial port settings can be
accomplished using any of four methods:
oVLINX ESP Manager Software for Windows allows
configuration via a network connection or directly from
the Ethernet port of a computer (using an Ethernet
crossover cable).
Web Server allows configuration via the network using
o
any web browser.
o
Telnet allows configuration via the network by accessing
the setup configuration menu.
o
Console Mode allows configuration through an RS-232
serial port in using a VT100 Terminal Emulation program
and an RS-232 crossover cable.
•Virtual COM Driver Software for Windows - installs virtual
COM ports, viewable in the Windows Device Manager under
Ports (COM & LPT). Virtual COM port provides access to any of
the ports on the ESP901 and ESP902, like any other serial port
(legacy, PCI, USB or PCMCIA) on the computer. Any program
running on the computer and using Windows-based COM ports
can access the serial devices attached to the
LAN becomes transparent to the serial device and the software
running on the PC.
communications in Virtual COM Port or Paired Connection
modes. This feature restores the connections if communications are
temporarily lost at either end due to loss of power or the Ethernet
connection.
The ESP901 and ESP902 Serial Servers enable communication with
serial devices over a LAN or WAN. Serial devices no longer are
limited to a physical connection to the PC COM port. They can be
installed anywhere on the LAN using TCP/IP or UDP/IP
communications. This allows traditional Windows PC software access
to serial devices anywhere on the LAN/WAN network.
Direct IP Mode
Direct IP connections allow applications using TCP/IP or UDP/IP
socket programs to communicate with the asynchronous serial ports on
the
Serial Server. In this type of application the Serial Server is
configured as a TCP or UDP server. The socket program running on the
PC establishes a communication connection with the
The data is sent directly to and from the serial port on the server. When
using UDP protocol the server can be configured to broadcast data to
and receive data from multiple IP addresses.
Virtual COM Mode
Install Virtual COM Mode allows the user to add a driver, to provide a
virtual COM port on the computer. The new COM port shows up in the
Device Manager. Windows programs using standard Windows API
calls are able to interface to virtual COM ports. When a program on the
PC opens the new COM port, it communicates with the remote serial
device connected to one of the ports on the
Serial Server.
Serial Server.
After connection, the LAN is transparent to the program and serial
device. Applications are able to work just as if the serial device is
connected directly to a physical COM port on the computer. The virtual
COM port software converts the application’s data into IP packets,
sends it across the network to the
Serial Server, which converts the IP
packet back to serial data and sends the data out a serial port located on
the
Serial Server.
To use this mode, the
Serial Server must be set to either TCP/server or
UDP/server with a designated communication port number. The virtual
COM driver is the TCP or UDP client.
Paired Mode is also called serial tunneling. In this mode any two serial
devices that can communicate with a serial link will be able to
communicate using two
Two
TCP or UDP client and the other as a TCP/UDP server. When setting
up the server the remote IP address section must contain the address of
the client. This will allow the client’s IP address to pass the IP addressfiltering feature of the server. Conversely, the Remote IP address of the
client must contain the server’s IP address. Both communication port
numbers must be the same.
Heart Beat
The Heart Beat protocol connection provides a reliable
communications connection in
Connection Mode
communications are temporarily lost at either end due to loss of power
or Ethernet connection.
Without this feature a device that loses a connection and stops
communicating would not be able to reconnect without human
intervention. A TCP data connection can be lost when there is a power
failure or temporary loss of an Ethernet connection on either the client
or server. If a loss occurs the Heart Beat feature will try to reconnect
the TCP data connection every five seconds until communications is
established again. The Heart Beat feature is available for use in
COM Port Mode and Paired Connection Mode. This is not available
when using a UDP application.
Serial Servers and the LAN.
Serial Servers are connected to a network, one configured as a
For descriptive purposes this Quick Start Guide considers a typical
configuration consisting of a PC connected via an Ethernet LAN to an
ESP901 or ESP902 Serial Server connected to the RS-232 port of a
serial device.
Hardware Setup
Figure 2. Typical Hardware Setup
Step 1: Connect the Serial Server to the network using a standard
network cable.
Step 2: Connect the
device.
NNoottee::
If the serial device is configured as a DCE use a straight-through serial
cable. If the serial device is configured as a DTE use a crossover (null
modem) cable.
Serial Server to the RS-232 port on the serial
Step 3: Set all the DIP switches to the OFF position.
Red - power is applied
Yellow – 10BaseT Ethernet connection established
Green – 100BaseTX Ethernet connection established
Ready
Flashing Green – system is ready
Figure 5. Indicator Lights
Ethernet Connector
The Serial Server has a standard RJ-45 receptacle mounted in the top
edge of the chassis. The Serial Server can be connected to an Ethernet
hub, switch, or wall plate using a standard straight-through RJ-45
(male) Ethernet cable. To connect directly to an RJ45 Ethernet port on
a PC or laptop a crossover Ethernet cable must be used.
NNoottee::
Refer to Appendix D for details on Network Cables
Power Connector
Plug the ultra-miniature phone plug from the included power supply
into the power jack and then plug the supply in. When power is applied
the Red power light will illuminate. The tip of the power plug is
positive; the sleeve is negative.
Reset Button
This switch resets the unit, similar to the effect of removing/applying
power. The Reset switch is recessed to avoid accidental operation. To
reset the unit, insert a small plastic tool, press lightly and hold for three
seconds. The Link and Ready lights will go out and then come back on.
RJ-45
female
Reset
Off
Figure 6. Top View of ESP901 and ESP902 (when mounted vertically)
A triple DIP (dual inline package) switch allows the Serial Server to
be placed into
the ON position the
configuration of the
through the serial port on the ESP901 or Serial Port 1 on the ESP902)
from a PC running a terminal program such as
the
Serial Server enters Console Mode the Console Mode screen will
appear in the HyperTerminal program window. The serial port settings
must be 8-N-1 at 9600 baud.
Console Mode. When all three switches are moved into
Serial Server enters Console Mode, allowing
Serial Server (using an RS-232 connection
HyperTerminal. When
Figure 7. The Console Mode (Server) Screen in the
HyperTerminal Window
When any of the DIP switches are switched back to the OFF position,
the Serial Server will revert to the mode it was in before Console
Mode.
NNoottee::
The Serial Server can be put into Console mode using either of two
methods:
1. Switching all the DIP switches to the ON position
2. With any DIP switch in the OFF position set the Server
Console Mode by placing all the DIP switches into the
Making Hardware Connections
Default Mode
When
Default Mode is selected and the server properties are Updated
(
Saved) all the configuration settings return to their default values.
Console Mode
In Console Mode the Configuration Menu can be accessed from a PC
by connecting its RS-232 serial port to the ESP901 serial port or
ESP902 Serial Port 1. Since the computer is a DTE device, and the
serial ports are configured as DTEs (with DB-9M connectors), a null
modem crossover cable must be used.
In
Console Mode the default serial port settings are: 9600 baud, 8 data
, No parity, and 1 stop bit. From Windows, HyperTerminal with
bits
VT100 terminal emulation can be used for
configuration.
Upgrade Mode
In Upgrade Mode firmware can be uploaded from a PC via its serial
port to the ESP901 serial port or ESP902 Serial Port 1. Upgrading also
can be accomplished via the network connection, using the ESP
Manager software and a virtual COM port.
NNoottee::
Refer to Chapter 5 for details on Serial Server Configuration settings.
See Chapter 12 for Serial Server default parameters.
NNoottee::
Refer to Chapter 9 for details on Console Mode
Console Mode
NNoottee::
Refer to Chapter 8 for details on Upgrade Mode
RS-232 Mode
In RS-232 Mode the currently selected serial port is configured as an
RS-232 interface supporting eight RS-232 signal lines plus Signal
Ground and is configured as a DTE, like a computer. Signals are single
ended and referenced to Ground. To use handshaking, Flow Control
must be set to RTS/CTS during Configuration.
NNoottee::
Refer to Appendix A for RS-232 connection pin-outs.
In RS-422 Mode the currently selected serial port is configured as an
RS-422 interface supporting four RS-422 signal channels with full
duplex operation for
CTS (Clear To Send). The data lines are differential pairs (A & B) in
which the B line is positive relative to the A line in the idle (mark)
state. Ground provides a common mode reference. To use handshaking,
Flow Control must be set to RTS/CTS during configuration.
Receive, Transmit, RTS (Request To Send) and
NNoottee::
Refer to Appendix B RS-422 connection pin-outs.
RS-485 Mode
In RS-485 Mode the currently selected port is configured as an RS-485
interface supporting transmit (TX) and receive (RX) signal channels
using 2-wire, half-duplex operation. The data lines are differential with
the Data B line positive relative to Data A in the idle (mark) state.
Ground provides a common mode reference.
NNoottee::
Refer to Appendix C for RS-485 connection pin-outs.
RS-485 Receiver Biasing
RS-485 Receiver Biasing
if the network does not supply it. Remove the two side-cover screws of
the
Serial Server, slide the cover off and re-position the bias jumpers
(shown open in the figure below) to enable biasing (shorting).
can be implemented from the Serial Server
Figure 10. Internal Setting to Select RS-485 Bias
NNoottee::
(For more information on RS-485 Receiver Biasing, see B&B
Electronics RS-422/485 Application Note available at www.bb-
The Windows-based ESP Manager and Virtual COM Port software
makes configuration fast and easy. If using Windows, installing the
ESP Manager software and setting up virtual COM ports to configure
the
Serial Server is recommended.
Software Installation
The VLINX ESP software includes:
• ESP Manager
• Install Virtual COM Ports
• Uninstall Virtual COM Ports
Automatic Installation
Step 1a: Inserting the VLINX CD in the CD-ROM should
automatically launch the Install Shield Wizard.
Manual Installation
Step 1b: To manually start the software installation, from the
Windows Desktop, click Start button. At the Run command
line type
the CD ROM.)
Figure 12. The Run Dialogue Box
The Install Shield Wizard window will be displayed.