Campbell LoggerNet, Instruction Manual, Page: 105 / 580

Section 4. Setting up Datalogger Networks
All of the COM ports which are set up and recognized by Windows will be
shown in the Available Ports list. Select a COM port from the list and press
Add Port to add the port to the modem pool. To delete a COM port from the
pool, select it in the Serial Port Pool box and press Remove Port .
When a SerialPortPool is added, LoggerNet will search for other
SerialPortPools in the network map and add all of the serial ports
specified in the existing SerialPortPools to the new
SerialPortPool.
NOTE
4.2.4.22 TerminalPortPool
The TerminalServerPool is used to allow LoggerNet to call, by phone, multiple
remote dataloggers, when there is more than one phone line and modem
available to make the connections.
The TerminalServerPool uses an IP connection to reach a modem. This type of
modem pooling is generally accomplished using devices known as terminal
servers. Examples of this kind of device include the following:
•
Lantronix EDS8PR
•
Cisco 2500 Series
•
PC Micro Net Modem Software
When these products are used, software is often installed on the
host computer (LoggerNet PC) that will define a local serial port
(virtual serial port) that redirects to the IP-based service provided
by the terminal server. Serial Port Pooling is used when virtual
serial ports are installed.
NOTE
Terminal Server Pooling is an alternative to using redirected serial ports. In
Terminal Server Pooling, TCP/IP is used to communicate with one or more
terminal servers. In this case, the LoggerNet server makes TCP connections to
the terminal server and sends commands to the modem. If the terminal server
supports the serial port protocol RFC 2217, select the check box. This allows
LoggerNet to use additional commands to control serial port characteristics
such as baud rate, word length, stop bits, and handshaking. Using the terminal
servers directly may simplify the use of the system in that it would eliminate
the driver that would otherwise be used to redirect a serial port. Since
implementations of terminal servers (including those that support RFC 2217)
can vary, it may make sense to verify compatibility before purchasing
hardware.
With pooled devices, multiple terminal server/phone modem combinations can
be specified for each datalogger. That way, LoggerNet is not restricted to the
use of a single base modem when calling a particular station. When calling a
station, LoggerNet will decide which modem from a group (pool) of modems
to use. Preference will be given to a modem based on availability and past
performance.
Each remote phone modem and datalogger has its own TerminalServerPool
device.
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