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Fig. 2. Network configuration of the IP Network-based Signal Control System
4
Problem of the IP Network-based Signal Control
System
The IP Network-based Signal Control System has achieved simple construc-
tion and high reliability by connecting between the logical part in a machine
room (such as an existing electronic interlocking) and the wayside devices
with a double optical network. However, existing electronic interlockings have
an internal optical network called S-LAN. The system configuration of con-
necting to another optical network does not offer benefits in reliability and
cost-effectiveness. Moreover, because the FCP does not have the I/O function
like an existing field device controller and is specialized in logical processing,
the process of FCP should be consolidated into the process of an existing
logic unit of one computer (see Figure 3). Therefore, the development plan
for a new Integrated Logical Controller was made.
5
Overview of the Integrated Logical Controller
The current logical part of the machine room has a complex configuration that
consists of multiple logical units which cooperate for controlling the signal
devices in the station yard. This complexity remains a problem in the signal
control system after the development of the IP Network-based Signal Control
System, because a lot of work is still required for the design, construction, and
inspection. To solve this problem, we are developing the Integrated Logical
Controller (LC), which covers the function of controlling all signaling devices
in the station yard with one logical controller, by simplifying the system
configuration and by integrating the control logic. [5],[6]
In the LC, the logical units and the control parts are integrated into one
logical controller, and the connections with wayside devices are combined for
transmission of information by optical cables. As a result, this feature brings
easiness in design, construction and inspection because of the simplicity of
