Setting Up Lines
38 IOLAN Device Server User’s Guide, Version 1.0
Virtual Mode ms
Vmodem is a feature of the Device Server that provides “modem like” communication between two
Device Servers on a network or between a Device Server and a host. This feature behaves like two
modems connected across a telephone line. Typically, you use the Vmodem feature when you have
multiple devices communicating with a central site. With just a single IOLAN Device Server at each
end of the network, you don’t need to use multiple modems, avoiding the associated costs of calls and
connections.
The data is sent in raw format from the virtual modem and can be received by another Device Server
or a host. This data can be sent automatically using the Monitor DSR option and then configuring the
host and port number of the receiver; if the receiving side is also a Device Server, set the Line
Service to Rev Raw or Vmodem (Rev Raw if the Device Server is only receiving, Vmodem to
initiate bidirectional data flow) and the Device Server port that the data is coming in on (this should
match the port number on the sending Device Server). Or, you can manually start a connection by
typing ADT<ip_address>,<port_number> and end the connection by typing +++ATH. The
ip_address can be in IPv4 or IPv6 formats and is the IP address of the receiver. For example,
ADT123.34.23.43,10001
BIDIR
When you configure BIDIR, you are creating a bidirectional raw connection, meaning that the
connection can be initiated from either the ethernet or serial side.
UDP
When you configure UDP, you are setting up a range of IP addresses and a port number that you will
use to send UDP data to or receive UDP data from. For example:
The UDP configuration window, taken from the DeviceManager, is configured to:
zUDP Entry 1
All hosts that have an IP address that falls within the range of 172.16.1.1 to 172.16.1.25
and listen to Port 33001 will receive UDP data from the serial device. The serial device will
only receive UDP data from the hosts in that range with a source Port of 33001.
zUDP Entry 2
All UDP data received from hosts that have an IP address that falls within the range of
172.16.1.20 to 172.16.1.50 and Port 33010 will be sent to the serial device. The Device
Server not send any data received on its serial port.