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A full three-port isolation is also provided. The power supply section is in fact galvanically isolated from both the
analogue multiplexing section and from the RS-485 serial line.
Each input channel is also DC-isolated from the input GND by two non-polarised capacitors. The dual capacitor
solution, usually not to be found on comparable products, avoid the need of having a single common ground for all
input signals. In this way, it is also possible to connect to any “floating” loop without any loss of isolation
In general, the three-port isolation combined with the dual-capacitor approach result in an effective and reliable
solution, with such advantages as:
•
undesired ground loops can be easily avoided;
•
existing isolation between different ports can be preserved;
•
very low risk of disturbing the 4/20 mA loop signal, also in case of fault.
I fact, the Mux2700 architecture is such that any internal single fault never result in any interference with an input
connected 4/20 mA loop. For this reason, the MUX 2700 can be used as a monitoring device within safety-sensitive
applications.
3.7 Software architecture
The Mux2700 HSM is not normally intended to be designed by the user in a specific application, but to be used as
part of the Elcon HART Interface Solutions (H.I.S.) offering, which includes a set of compatible Maintenance
Workstation solutions.
This means that the user doesn’t have to worry about either the internal details of the unit software functions nor
about the specific RS-485 protocol features. In fact, the Maintenance Workstation software make most of these
details “invisible” to user by providing an user-friendly, graphical man-machine interface.
When you have any special need or problem, please contact Elcon for additional information.
IM-ENG-116/GB
