Technical data

Introduction
Documentation Number: LES40xA-1105m Chapter 1 3
Black Box Corporation - 1000 Park Drive - Lawrence, PA 15055-1018
www.blackbox.com -- Tech Support and Ordering: 724-746-5500 - Fax: [phone]
• Heart Beat Connection - selectable protocol ensures reliable
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.
Communication Modes
The 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
Serial Server. 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.
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.
Introduction
4 Chapter 1 Documentation Number: LES40xA-1105m
Black Box Corporation - 1000 Park Drive - Lawrence, PA 15055-1018
www.blackbox.com -- Tech Support and Ordering: 724-746-5500 - Fax: [phone]
Paired Mode
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
Serial Servers and the LAN.
Two
Serial Servers are connected to a network, one configured as a 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 address-filtering 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
Virtual COM Port Mode or with Paired Connection Mode.
This feature restores the connection if 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
Virtual COM Port Mode and Paired
Connection
Mode. This is not available when using a UDP application.