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5.1.2.2 Virtual Server Mode
Though high security is the key feature of standard client mode, can’t
accessed by other devices thru network is also a drawback. To take the
balance between the security and connectivity, the Ethernet module
provides a virtual server mode to meet the both end. While working at this
mode, the Ethernet module emulates a PLC with station number of 255.
There are only R0~R1999 can be accessed of this virtual PLC. When the
command message is for station 255, the Ethernet module will interpret
the message and act upon that message; this is true for all the messages
whether it comes from serial port or from network. The Ethernet module
act as a medium, the status of PLCs can store in it for outside world
access. The outside world can put the command status in it for PLCs
access. The virtual server mode is an option for client working mode,
which means while act as virtual server the master PLC still can access
the slave PLCs that attached to network.
5.2 Hardware Installation
5.2.1 DIP Switch Setting
5.2.1.1
Termination resistor installation(FBs-CM25E/CM55E)
In order to meet the termination requirement of RS485 network, all
Ethernet modules equip with a set of built-in termination resistor to ease
the field installation. The termination function can be setup by the DIP
switch seen from the front cover as follow.
T
N
When both switches are at T position, it means termination resistor is in
effective. When at N position means no termination resistor attached by
this module. When implementation, there are only two modules that
located at opposite far side need to terminated. Excessive termination will
over load the whole network thus must be avoided.
5.2.1.2
Password protection setup
When the password has been entered (enabled), the user will be
requested to enter a matched password each time when perform the
configuration via configuration utility ‘ether_cfg.exe’. In other words, in
case the user forget the password then he/she no longer can modify the
module’s configuration. To prevent this situation from occuring, there also
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