Foxboro SCD5200 Remote Terminal Unit

Foxboro SCD5200 Remote Terminal Unit

DESCRIPTION

The SCD5200 is a multi-nodal Remote Terminal Unit with advanced data integration, time synchronization, and programming capabilities. Its primary slave interfaces are based on the dual communication module which provides DNP3 Slave and IEC 60870- 5-101 Slave functions. The SCD5200 uses these protocols to communicate and integrate with multiple remote master control centres. Each SCD5200 rack mounted cardfile can support Power, CPU, Communications and IO modules. The range of IO modules is extensive, covering all aspects of IO at a wide range of input voltage levels. Each IO processor is intelligent, providing on board pre-processing and capture of sequence of events information.

REAL-TIME DATABASE AND ENVIRONMENT

As shown in Figure 1, the SCD5200 environment consists of a central real-time database which is kept up to date by a variety of independent processes. These processes are supported by the embedded operating system executive.

 IO Time Sync – The real-time clock on each processor is used to synchronize the clocks on all intelligent IO modules. 

 IDF Intrinsic Data Functions – Event driven preconfigured functionality is very fast and often used for implicit conversions of IO information. 

 Calculations – Up to 3 calculations tasks can be programmed by the user. Each task is written as a State Machine or a Procedural Logic using the dedicated State and Logic Language [SALL]. 

 PLC Engine – In addition to state transition calculations, the SCD5200 provides a PLC executive which operates in a more traditional PLC cycle, reading input snapshots, calculating outputs, writing outputs. The engineering of IEC1131 programs is provided using 3rd party programming tools. 

 IO/COMMS/OptoNet – Almost all functionality is provided through the Electrobus and OptoNet interfaces. The Electrobus interface supports the IO and Communications modules and the OptoNet functionality supports the transparent transmission of the real-time database from node to node. 

 IEC61850 Client Stack – A separate stack process is maintained to allow the IEC61850 Client services to operate. 

 IEC61850 Server Stack – A separate stack process is maintained to allow the IEC61850 Server services to operate.

Multi-Slot Cardfile Formats

The SCD5200 is provided with a passive parallel backplane which makes it possible to provide a number of formats with varying number of IO slots. Each format allows for one CPU. The most popular cardfile format for the SCD5200 is a 19” rack file which includes a wide range Power Supply, a COE [CPU, OptoNet, Ethernet] variant of the CPU module, and space for up to 10 standard width IO modules.

Each rack can be interconnected by use of OptoNet cables which allow for a scalable solution involving multiple computing nodes. Higher communications densities can be accommodated by the use of the 5-slot cardfile. In this case a COPE [variant of the CPU module] supplies backplane power which avoids the need for a separate wide range power supply. This 5 slot file can be located in smaller spaces where a 19” rack solution might not be feasible.

Higher availability architectures demand alignment of the CPU with specific areas of plant control and distributed among many locations on a site using OptoNet or High Speed Ethernet. The 3-Slot cardfile provides an ability to create highly distributed architectures where minimal communications and IO are required.

Multi-Backplane Cardfile Formats

The SCD5200 may be constructed in a semi distributed available architecture by using Multiple Backplanes in a 19” Rack. The following MultiBackplane cardfiles are available:

 2 x 5-slot – providing up to 2 COPE modules per 19” rack 

 3 x 3-slot – providing up to 3 COPE modules per 19” rack.

CPU OPTONET AND ETHERNET (COPE AND COE) MAIN PROCESSOR MODULE

The SCD5200 COPE Board has an industrial processor with an Electrobus Interface and includes:

 32-bit industrial processor (including cache and floating point co-processor) 

 2 serial ports (configurable RS-232/RS-485) 

 128 KB of non-volatile static RAM 

 16 MB or 64 MB RAM (64 MB RAM versions required when using configurations supporting IEC 61850) 

 8 MB internal flash file 

 Dual 10BaseFL/100BaseSX Ethernet ports with auto negotiation support 

 On-board real-time clock 

 40 W regulated wide input voltage dc power supply 

 Single OptoNet node (2 optical ports). The SCD5200 COPE Board supports the following: 

 OptoNet High-speed optical redundant token passing local area network 

 COM1 port RS-232 Diagnostic Utility Foxboro Evo™ Remote Terminal Viewer (RTV) 

 COM2 port RS-232/RS-485 DNP3 Master DNP3 Slave Modbus Master Modbus Slave IEC 60870-5-101 Master GPS Clock User configurable serial interface