OLE for Process Control Software for Automation Controllers

OPC – OLE for Process Control was originally designed for accessing data from network data servers, OPC interfaces are being used in many places in today’s software environment. At the lowest level OPC servers used to exchange data between a physical device and an application. The architecture and design also allow the construction of OPC Servers that access data from different OPC servers from different devices running on different nodes. This includes application to application interfaces. Current enterprise software systems are being fielded that rely on OPC for database access, maintenance, alarming, MMI/SCADA, and general system integration at the level of ladder and program development and control.

current development at Delta Tau are underway to move PMAC-NC and PMAC executive in this direction so that rather than directly talking to PMAC (Programmable Multi Axis Controller) using PCComm32 on the host computer the PMAC OPC Server will be used. In doing so a single PMAC-NC or PMAC Executive application will be able to communicate with other controllers or control multiple PMAC running in physically separate locations of different computers. Further enhancements to these Delta Tau tolls will decompose them into COM compliant objects that will allow the developer to access specific capabilities from their own custom software.

PLC Driver Software

The driver supports multiple clients. The maximum number of clients has been arbitrarily chosen as 5. It can be extended if required. The multiple client drivers are useful for the following.
1. The maximum number of registers for one Modbus transaction is 125. If the numbers of I/O signals require more than 125 registers one can use multiple clients for data access from different register segments.
2. In some micro systems, more than one PLC unit with the different IP addresses may be used. The micro can concurrently communicate with all the PLC units by setting up multiple clients.

The driver provides three utility functions to the micro application module. All the functions return a status code and the data, if any.
a. Init Function
The application should first invoke this function with the following parameters: the upper and lower limit for the registers that will be used for data exchange, IP address of the PLC and the polling period. The application program specifies the frequency at which the “read register” command is to be sent to the PLC.

b. Read Function
The application module uses the Read function to retrieve the data from any register range so long as it is within the declared set. The application should first test the status code for error before updating the data field within the device record.

c. Write Function
When a high-level program sends a command (analog or digital or any) to a device, the application module encodes the command in an appropriate format and invokes the write function to post the information to the client task.

Process Control Security Requirements in SCADA Field

The Process Control Security Requirements Forum (PCSRF) was to develop and complete a SCADA Field Device Protection Profile. The protection profile will list the security requirements for field devices such as PLC’s, PAC’s, RTU’s and IED’s.

The protection profile is an opportunity for the asset owners, vendors, industry organizations, government organizations and other interested parties to provide a clear and comprehensive set of security requirements for the next generation of field devices. Vendors will then be able to develop field devices that meet the protection profile requirements and have those devices independently tested and certified by an internationally recognized third party.

PCSRF has chosen to use the common criteria methodology to specify functional and assurance requirements. The common criteria have a precise language and methodology that enables for clear specification and objective testing. To achieve this, the common criteria sacrifices readability and are not appropriate document for general reader to learn guidelines or best practices. It may not be easy for even a subject matter expert in SCADA Field Devices to understand some of the later sections of the protection profile text.

To encourage participation each milestone deliverable in this project will have a section with the draft protection profile text and a section explaining the protection profile text.

Automatic Gates using PLC Mitsubishi

PLC Type FX-Mitsubishi , Name Input / Output PLC :

INPUT PLC :
X000 ; Area Sensor 1.
X001 ; Area Sensor 2.
X002 ; Area Sensor 3.
X003 ; Area Sensor 4.
X004 ; Limit Switch for Open gate.
X005 ; Limit Switch for Closed gate.

OUTPUT PLC :
Y000 ; Contactor for Electric Motor ( Open Gate ).
Y001 ; Contactor for Electric Motor ( Close Gate ).

PLC Programming for Automatic Gates using PLC Mitsubishi

Reading Ladder PLC Programming for Automatic Gates using PLC Mitsubishi :

Step 1 :
Open Gate
a.If X000 = OFF AND X004 = OFF Then M0 = ON (Hold ON).
b.If M1 = ON AND X001 = OFF OR X002 = OFF Then M3 = ON.
c.If M0 = ON OR M3 = OFF Then Y000 = ON.

Step 2 :
Close Gate
a.If X004 = ON AND X003 = OFF AND X001 = ON AND X002 = ON AND M4 = OFF AND X000 = ON Then M1 = ON (Hold ON).
b.If M1 = ON AND X001 = ON AND X002 = ON Then M2 = ON.
c.If M1 = ON AND X001 = ON AND X002 = ON AND X005 = ON Then M4 = ON AND M1 = OFF.
d.If M2 = ON Then Y001 = ON.

Please Download Programming for GX Developer :
Automatic Gates using PLC Mitsubishi

See : Automatic Gates

Verification and Optimization of a PLC Control Schedule

Nowadays, the verification of hybrid system is a popular topic in the formal method community. The presence of both discrete and continuous phenomena in such systems poses an inspiring challenge for our specification and modeling techniques, as well as for analytic capacities. This has led to the development of new, expressive models, such as timed and hybrid automata, and new verification methods, most notably model checking techniques involving a symbolic treatment of real time aspects.

The important examples of hybrid (embedded) systems are process control programs, which involve the digital control of processing plants, e.g. chemical plants. The classes of process controllers that are of considerable practical importance are those that are implemented using Programmable Logic Controllers (PLCs).

To assess the capacity of state of the art formal methods and tools for the analysis of hybrid systems will describe on the design and verification of PLC program in chemical plant. The using of SPIN model checker for both the verification of a process control program for the given plant and the derivation of optimal control schedules.

As the symbolic calculation of real time model checkers can be quite expensive it is interesting to try and exploit the efficiency of establish non real time model checkers like SPIN in those cases where promising work around seem to exist. It handled the relevant real time properties of the PLC controller using a time abstraction technique.

NSLS Control System Interface to PLC

The PLCs have been extensively used in industry to automate a variety of control a d monitoring functions in many years. They are flexible, versatile and are built to withstand harsh factory conditions. However their role was confined to industries due to their slow response, slow processing power and lack of communication standards. Because of recent evolution towards PLCs with fast processors, a variety of compatible I/O products and communication adapters that support TCP/IP network, the PLCs have made a quantum leap into the arena of distributed control systems for large accelerator facilities.

The control system at the NSLS has a two-level distributed architecture consisting of HP/c8000 series workstations for the high-level (the operator level) and 80 VME-based microprocessors subsystems for the lower level. The communication is high speed Ethernet. The micros are responsible for the control and monitoring of the storage ring hardware. The equipment to be controlled, dictates the type of I/O boards for a micro. The I/O peripherals include ADC, DAC and digital I/O cards in the micro crate.

Though fast and reliable, VME I/O cards are very expensive and may not be required when controlling and monitoring devices with slow response. PLC was considered as an alternative. The hardware engineers also preferred to replace the traditional digital circuit hardware with PLC.

Development of PLC Based Controls at NSLS

The decision factors when selecting the Modicon products were costs, technical support, availability of a wide range of inexpensive I/O modules and networking solutions. The introduction of the MODBUS TCP protocol combined with the networking hardware by the Schneider Corporation, has greatly simplified the interface between the control systems of the PLCs.

At NSLS two types of processors are used. One is the TSX Quantum Controller. The logic is stored and run in the Quantum Controller. The processor communicates with I/O module using the Modbus Plus protocol. An Ethernet module connected to the processor via quantum back-plane provides the link to control system. The other processor is from the family of TSX Momentum products which include processor adapters, communication adapters, option adapters (to provide the processor with additional networking capability), and a variety of I/O modules. The modular design of the adapter and the simple plug-in and wiring of the products allow easy integration of a system that meets the NSLS requirements.

The concept software is used for PLC Program development. This complies with the Microsoft Windows GUI interface and the IEC 1131-3 standard for PLC programming. The concept software provides great development and debugging environment and generates documentation for the programmers.

ABB Advant OCS – Advant Master DCS

The DCS is a control system which collects the data from the field and decides what to do with them. Data from the field can either be stored for future reference, used for simple process control, use in conjunction with data from another part of the plant for advanced control strategies.

Advant OCS (Open Control System) is an ABB solution for operators to improve their manufacturing productivity and achieve sustainable competitive advantages.

In 1992, based on the success of the Master systems in the 80’s, the Master system began its evolution to Advant OCS. This evolution introduced high capacity controllers and I/O with an improved redundancy scheme. Also included were modern UNIX workstations, and in 1996 S800 I/O was added providing modular flexible remote I/O.

In 2000, Advant OCS with Master Software began its next step in the evolution process with the introduction of industrial IT enabled products. A versatile and complete range of process I/O systems within the Advant family enables optimal user configurations:
S100I/O – A rack-based I/O system for AC400 controllers.
S600I/O – A rack-based I/O system for AC100 controllers.
S800I/O – A highly modularized and flexible I/O system.

Numerous characteristics and function facilitate and improve operation, monitoring, and reengineering of each process in a company. 800xA Operations (Process Portal) and the proven AdvaCommand for UNIX solution (based on HP-UX) are available as an operator station for Advant OCS with Master software.

The intuitive operator software provides consistent access and interaction with data from multiple control and I/O to plant and enterprise information.

Controller System for Industrial Automation

The element linking the measurement and the final control element is the controller. Before the advent of computers, the controllers are usually single-loop PID controllers. These are manufactured to execute PID control functions. These days, the controllers can do a lot more, however, easily 80 to 90% of the controllers are still PID controllers.

It is indeed difficult to say that analogue controllers are definitely better than digital controllers. The point is, they both work. Analogue controllers are based on mechanical parts that cause changes to the process via the final control element. Again like final control elements, these moving parts are subjected to wear and tear over time and that causes the response of the process to be somewhat different with time. Analogue controllers control continuously.

Digital controllers do not have mechanical moving parts. Instead, they use processors to calculate the output based on the measured values. Since they do not have moving parts, they are not susceptible to deterioration with time. Digital controllers are not continuous. They execute at very high frequencies, usually 2-3 times a second.

Analogue controllers should not be confused with pneumatic controllers. Just because a controller is analogue does not mean it is pneumatic. Pneumatic controllers are those that use instrument air to pass measurement and controller signals instead of electronic signals. An analogue controller can use electronic signals. Compared to pneumatic controllers, electronic controllers (can be analogue or digital) have the advantage of not having the same amount of dead time and lag due to compressibility of the instrument.

Honeywell Experion Process Knowledge System

Experion is Honeywell’s unified system for process, business, and asset management that help industrial manufacturers increase their profitability and productivity.

Experion takes customers well beyond Distributed Control System (DCS) functionality with advanced automation platform solution and innovative application integration to improve business performance and peace of mind. And there’s no need to worry about upgrading from TDC2000/TDC 3000 or Total Plant Solution (TPS).

The unique, patent pending design of series C combine sleek styling and function to provide process I/O with reduce footprint, easier installation and maintenance and longer life. The series C form factor benefit extend to multiple modules, such as the series C C300 controller, the Fieldbus Interface Module, the Control Firewall, and HART analogue modules.

The Control Execution Environment (CEE) is the common core software used in the various controllers supported by ExperionTM. This includes the C200 Process Control, the C300 Process Controller, the Application Control Environment (ACE) and the C200 Simulation Environment (SIM-C200). The CEE provides an execution and scheduling environment where control strategies are configured from a rich set of standard and optional function block a single builder tool, Control Builder.

Function Block are grouped and wired together in a container to perform s specific control function such as a valve control strategy. The Control Execution Environment (CEE) supports two types of containers: the Control Module in which continuous and discrete controls are combined, and an SCM, which is used foe sequence control. Function block support the complete control application range, such as continuous, discrete and batch control.

Main Feature of PLC

PLC control system is that it regards PLC as control key component, utilize special I/O module to form hardware of control system with a small amount of measurement and peripheral circuit, to realize control to the whole system through programming.

1. High Reliability
Strong anti-interference quality and very high reliability are the most important features of PLC. In order to make PLC work stably in strong interferential circumstance. Many techniques are applied in PLC. Software control instead of relay control mode can decrease faults which are brought about by original electric contact spot outside working badly. Industrial grade components made by advance processing technology can resist interferences, and self diagnosis measures of watchdog circuit for protecting memory can improve performance of PLC greatly.

2. Good Flexibility
There are several programming languages for PLC including ladder diagram, SFC, STL, ST and so on. If operator can master only one of programming languages, he can operate PLC well. Every who want to use PLC has a good choice. Based on engineering practice, capacity and function can be expanded by expanding number of module, so PLC has a good flexibility.

3. Quality of Strong Easy-Operating
It is very easy to edit and modify program for PLC by computer offline or online. It is very easy to find out where the fault lie by displaying the information of fault and function of Self Diagnosing Function, and all these make maintenance and repair for PLC easier. It is very easy to configure PLC because of modularization, standardization, serialization of PLC.

Application Fields of PLC

PLC is widely applied in all industrial departments in developed countries, which is include steel industry, petroleum industry, chemical industry, automobile industry, construction material industry, machine manufacturing industry, etc. with the development of all kinds technology, function of PLC improve dramatically, therefore application scope of PLC has enlarged continuously.

1. Logical Control of Switch Signal
This is the most important function. The design idea of PLC is logical control of switch signal. PLC substituting for control of relay can realize combinational logic control, timing control, sequence logical control. The logical control of switch signal is used on single machine, for example injection molding machine, printer, modular machine tool, grinding machine, etc. it also can be used on automatic production line.

2. Motion Control
Proper motion control module possessing function of simulating motion law precisely control position and speed which is widely applied in processing machinery, elevator and robot.

3. Analog Signal Processing Control
PLC can realize digital – analog conversion and analog – digital conversion by means I/O analog module, and finish PID closed loop control. The function is used in some situation, such as temperature, liquid flow.

4. Data Processing
The newly PLC possesses mathematical operation function such as, arithmetic operation of integer, matrix operation, function operation, logical operation of word, complementary operation, transmit data, then finish collecting data, analyzing data, processing data.

5. Network Communication
PLC can communicate with other PLC, remote I/O module, can communicate with several PLCs, it can constitute DCS with intelligent device.

Application of PLC in Glass Industry

PLC was applied in glass industry in 1980s. Since then, PLC was assembled bit by bit. Nowadays PLC has been used in every procedure and every workshop to control material ratio, equipment of cold forging, the processing of flat glass, etc.

With development of PLC and enhancement of productivity demand, the control mode of PLC together with intelligent device is being applied in Glass Industry. Under the production of Float Glass, only PLC by itself can not finish control tasks because of complexity of control system and processing analog, a large number of data. Now we can use Bus Technology to construct the control mode of PLC together with DCS (Distributed Control System), in which DCS deal with data recording and analog controlling and PLC is responsible for position control and digital quantity control.

This kind of control mode can bring advantage of both DCS and PLC into full play to improve reliability and flexibility of control system. In the meantime in Production line of toughened glass, control system adopts to other control mode, that is to say, PLS as lower computer constitute DCS with industrial computer. This control mode gives full play to function of both PLC and Industrial Computer, in which PLC is responsible for position control and digital quantity control and Industrial Computer deal with data acquisition and display. In this mode human-computer interaction technology is conveniently used to improve function of control system.

Application PLC in Cement and Steel Industry

Nowadays, various control systems of DCS come into being in view of various conditions and various network forms through Bus Technology to achieve automation of production and management in factory. Existing DCS based on original control system in which PLC is widely used mode of SCADA, that is to say this kind of mode is composed of configuration software and PPLC. The SCADA mode is composed of host computer and PLC. Host computer contains master station and slave station. PLC as a lower computer to control real device, such as batching system of raw materials, kiln of coal mill, ball milling, shaft kiln, etc. due to openness and performance price ratio, this kind of DCS is widely applied in middle and small process control system, subsystem of large process control system in cement factory.

In the early 1980s our country began to import complete sets of production equipment for steel in which PLC is used for control system. At that time, there is tens of kind of brands of PLCs containing up to two hundreds of PLCs on a set of equipment. Nowadays, in view of advantage of combination with real machine PLC as lower computer has been used widely in production line for steel. PLC has played an important role in every procedure and machine, such as controlling temperature and pressure in boilers, lifting electrodes, feeding oxygen lance for steel, controlling cooling bed and etc.

Process Field Bus – Decentral Periphery (Profibus DP)

Profibus DP is an open, high speed and widely used field bus. It provides multi-master and master-slave communication in the field area. This field bus can accordingly be used for AC500 and AC31 control system series and for field-bus-neutral FBP devices (decentralized I/Os and intelligent switching devices) via the PROFIBUS-FBP connector.

The masters rule data traffic on the bus. When in possession of the bus access authorization (token), the masters can transmit data without an external request. The passive devices, known as slaves, do not receive any bus access rights; they acknowledge messages received, or respond to a query from a master. Baud rates from 9.6 kBaud to 12 MBaud are supported. A maximum of 126 devices can be operated on the bus.

Data exchange is handled predominantly in cyclical mode between master and slave. The requisite communication functions have been specified by the Profibus DP basic functions in accordance with EN 50170. Each master has full write and read access to its assigned slaves, but only read access to the slaves assigned to other bus masters. There is no direct data exchange between masters.

Profibus DP, the functionality at glance maximum 126 subscribers via amplifier and maximum 32 subscribers (master/slaves) per bus segment. Data transmission rate from maximum 12 MBit/s with a cable length of 100 m, and it is up to 93.75 kBit/s with 1200 m. Multi-master or master/slave communication. The bus access of the master is using token. Connection of the master CPU and the associated communication module is via a 9-pole SUB-D plug connector. Connection of slaves (CPU, I/Os and intelligent switching devices) is via FieldBusPlug.

Technology Integration for Home Automation

It is a fact that technologies change and evolve throughout time. This way, new technologies arise, which eventually replace those becoming obsolete.

Such is the case of the X10 protocol, obsolete and slow today when compared to other newer home automation technologies like UPnP (Universal Plug and Play).

For this reason, it is good to the usage of a services gateway like OSGi, which makes transparent to the user the actual underlying technology which provide the service, even if it should change at anytime.

The ideal proposal solution for a Home Automation System was the one where every device that might require a broadband connection can have a PLC interface to achieve this. This goal is achieved within the PLC integration in the UMU Home Automation device.

The OSGi functionality can be observed in the service developed by UMU that allows a user to manage X10 bulbs as IPvP UPnP devices. The X10 technology is limited and not as powerful as it would be desirable. By means of the OSGi developed service, a user will be able to manage his X10 bulbs by means of any UPnP IPv6 Control Point.

In this case the underlying technology is X10, but this is just an example of a non-IPv6 technology that is no accessible.

Information of Modbus RTU Developed by Modicon

Modbus RTU is an open master/slave protocol, and can be easily implemented on serial interfaces. Numerous automation systems have Modbus RTU interface as standard or optional features, and are thus easily able to communicate with the AC500 via its integrated COM1 and COM2 interfaces (RS232 or RS485). The Modbus is used not only in industrial applications, but also in building installations, in energy optimization systems, for long distance data transmission and for linking up operator panels.

The communication by polling, i.e. the master transmits a request to the slave and then receives the response. Both interfaces COM1 and COM2 can operate simultaneously as Modbus interfaces. The Modbus operating mode of an interface is set using the engineering tool.

The topology point-to-point is via RS232 or multi-point via RS485. With RS232, a maximum of one master and one slave is possible, while with RS485 one master and a maximum of 31 slaves can be operated. The maximum cable length is 15 m with RS232 and 1.2 km with RS485.

Data transfer max 187.5 Kb/s. each telegram has a 16-bit CRC appended. The telegrams permit process data (input/output data) to be written and read, either individually or in groups. The data are packed in the RTU format.

The transmission may vary. One widely used option is the RS485 bus physics, a twisted pair, shielded cable with terminators.

PLC Programming by Integrators

The complexity of dealing with integrators has been a surprise. Integrator companies in the irrigation market have been quite independent, with little independent review of their work. Their procedures for documentation of programming, their neatness of organizing wiring and panels, their usage of programming languages, and their exposure to PI algorithms for canal automation are quite varied. This means that nothing can be taken for granted – even if an integrator can list numerous completed projects,

Three items are of particular concern:
1. A good integrator will always understand hardware, installation, communications, and programming quite well. But it is rare that an integrator is familiar with modern canal control algorithms, and how they are tuned within a simulation model. This can be a problem if the integrators take unwarranted liberties in the programming of the control algorithms that supply as well as with the tuning constants.

2. Integrators sometimes embed numerous checks into their code with various hidden constants that can shutdown a gate or pump operation. The irrigation district operators (i) do not know these constants exist, (ii) do not know how to access them, (iii) must generally personally visit the PLC to change the constants should be changed. It believes all constants and alarm should be transparent and changeable from within the office via the SCADA system. A portable PC with a copy of the office HMI software can be used in the field to change constants if it is desired t make in-field adjustments.

3. The “control algorithm” for a gate (the algorithms that are published in irrigation literature) may only occupy 10% of the total programming handles numerous checks of equipment and sensors, consideration of gate inertia, and other factors.

SCADA Security for System Monitoring and Control Communication

Critical infrastructure systems include critical physical processes. These processes are controlled by automation systems which combine humans, computers, communications and procedures. Automation systems are used to increase the efficiency of process control by trading of high personnel costs for low computer system costs. They also contribute to improved performance by taking advantage of faster computer control instead of human reaction times. The automation systems are often referred to as process control systems (PCS) or Supervisory Control and Data Acquisition (SCADA) systems, and the widespread use of such systems makes them critical to the safe, reliable, and efficient operation of many physical processes.

Power system operation is becoming ever more complex in today’s deregulated environment. Maintaining reliable service depends on increasingly sophisticated control and protection algorithm and also the automation equipment. At the same time, system and device limits are being tested. Interconnected dependent systems give rise to new classes of relationships, both physical and economical. Increased deployment of protection schemes designed to allow increased loading of devices and operation closer to transient and static system limits heightens the possibility of unstable modes resulting from typical stimuli. Complex control at the EMS (Energy Management Systems) level worsens these issues.

The term SCADA (Supervisory Control and Data Acquisition) is used to represent the communications component and control architecture that provides control capabilities to a power system. Most often included are elements in a power system responsible for system monitoring and control communications. The term SCADA includes all automation elements for the electrical infrastructure: EMS, protective relaying, AGC (Automatic Generation Control), WAP (Wide Area Protection), communications, etc. the elements that make up a SCADA system provide the sensory and command interfaces between the bulk power system and its associated control functions.

SCADA Automation System Model

Some of the difficulties encountered in discussing security in an automation system are: the lack of security categories for operational data, the use of the same communication channels and network connections for multiple categories of data, and wide variety of equipment deployed having different subsets of capabilities between competing vendor’s equipment. The variations for both requirements and architecture that exist between companies within the same industry further aggravate these difficulties.

System requirements, data categories, and the system’s internal interdependences need to be identified to determine an effective strategy to secure the system’s operation. The model can also help identify certain single point of failure the system along with interdependencies that may not otherwise be obvious.

Object modeling summarizes system control element logically. This model captures the object role view of the automation and SCADA systems used in electric power systems, including the classes of objects that are present along with the ways in which they relate to each other (called roles). The roles may exist between one object to another directly, or they may be implied through the relationship of two objects to third (or others). The improved understanding provided by object modeling is essential to understanding security requirements for automatic systems.

GE Substation Automation Components

Software application
A powerful suite of flexible, user friendly software applications and graphical user-interface modules are available. These advance user interface and easy to configure tools enable improved date reporting and data base configuration management.

Network communications
A range of network components are available to tie and new legacy equipment into one unified system. GE can provide secure and reliable communications media based on experience and expertise in numerous network systems.

Intelligent Electronic Devices
A family of modular and flexible intelligent electronic devices is available for solving the biggest challenge of integrating relays from existing substations and new systems. Our relay family provides the latest for relay integration, protection, and control, with high speed, open standard peer-to-peer communication for connecting directly to the LAN.

Gateways/Servers
Robust system for monitoring a controlling substation device as well as for performance automation, IED gateways, and host communication functions. The systems have the processing power to monitor and control over 40 IEDs and thousands of I/O points.

Monitors and sensors
With a portfolio of sophisticated monitoring and diagnostics systems for critical substation equipment, remote monitoring of performance and critical fault detection is achievable. These advance systems enable you to improve performance and service reliability as well as extend the useful life of critical assets.

Feeder automation
Distribution Automation Remote Terminals equipped with auto-section-alizing and automation restoration software can dramatically reduce a customer’s outage frequency.

The System Benefits of GE Substation Automation System

GE Substation Automation seamlessly integrates the protection, monitoring, diagnostics, control, measurement, and software functions of your substation system. Below are the system benefits of GE Substation Automation system:
• Proactively identify fault before catastrophic failure occur.
• Manage fault detection, auto-sectionalizing, and auto-restoration.
• Enhance security and reliability with integrated protection, monitoring, and control.
• Monitor of status of all substation primary, protection, and control devices.

GE Substation Automation System also can centralize automation as following:
• Immediate access to remote locations from a centralized location.
• Enable predictive maintenance through analysis of operating conditions.
• Lower costs through centralized communications to remote substations.
• Common database enable predictive maintenance, volt/VAR control, and self diagnostics.
• Web enabled design affords resource location flexibility.

Improve asset management and enhance information management:
• Achieve tight system control through transformer and feeder load balancing systems.
• Extend equipment life and operate peak remote real-time performance monitoring.
• Eliminate redundant transducers, meters, event recorders, annunciation, and RTUs.
• Automation analysis of key operating condition for timely decision making.
• Quickly assess load management, load shedding, reactor and capacitor switching.

And lastly GE Substation Automation System can improve productivity:
• Adjust voltage, transformer loads, and feeder loads from central office PC or remote laptop.
• Improve equipment operating efficiencies through real-time monitoring and diagnostics.
• Fine-tune operations in real-time user-friendly, secure access.

Improved Solution for Substation Automation with GE Power Management

When it comes to managing your substation, the challenges can be difficult. Anything from unknown equipment status to unexpected outages can turn decision making into guesswork. GE is bringing an improved solution for your substation automation needs. With integrated solutions from GE Power Management and GE Harris Energy Control Systems, the total return on investment for your substation automation project can be even greater.

It provides comprehensive automated power management, protection, control, and monitoring solutions for substation automation. Systems are scalable and upgradeable, allowing for a minimal initial capital investment while maintaining the ability to upgrade.

In combining the hardware and software components required to efficiently integrate various power system IEDs. The GE substation Automation system provides standard network interfaces, open-layered multi protocol support, and centralized network management to efficiently communicate between generating plants, substation, and operation centers.

Legacy protocol devices can be combined with MMS/UCA2 and DNP 3.0 compliant IEDs or a host of other protocol including open ModBus/TCP and ModBus RTU over a high speed fiber optic communication network to accommodate the optimum combination of devices.

Comprise of communication equipment, protocol, gateway, HMIs, engineering tools, GE’s multi lingual UR (Universal Relay) family of IEDs and the D25 IED, the GE substation automation System directly interfaces with EMS and SCADA systems incorporating GUIs (Graphical User Interfaces).

Standardization (SOP) in Automation

The idea here is to create repeatable, high quality methods for operating and maintaining automation systems. These directives cover many of the things that would normally be covered in SOPs – how to manage changes for an automation project, how to submit funding requests, how to track money and time on an automation project. However, these directives also describe an automation system in detail.

Directives related to the field elements of the automation system might describe in detail how main-line pumps are controlled. Directives for the master station would outline how operator interface graphics should look.

Also, many companies that need to monitor and control remote processes spend significant time developing standards for communications between field station and the master station. Often these communication standards include detail memory maps for PLCs – indicating which register should be used to store alarms, set points, calculated points, etc.

Some companies extend this idea to the creation of “canned” automation sub-systems for common applications. For example, one pipeline has a “canned” compressor station automation sub-system. The sub-system consists of a GE 90/70 PLC running a base logic program that can support up to 12 compressors. When deployed, an engineer simply purchases the appropriate GE90/70 model and then customizes the base logic program to accommodate the correct number of compressors at the station to be automated. This “canned” approach can radically reduce the amount of engineering/technician time requires to deploy new compressor automation sub-system.

The Substation Automation System

The system used to monitor & control power systems and process shall take into account changes made in innovation cycles as well as new trend in utilities. UIS Substation Automation Solutions can meet all the demands of a distributed substation control system for both existing as well as newly built electrical substations.

The substation automation system is formed around a redundant network where the subsystems are physically distributed, logically integrated:
1. Bay level – consists of protection devices, IEDs, and measuring devices to be connected to Bay control units.
2. Station Level – consists of fiber optic substation LAN, serial bus for protection devices that can not directly connect to substation LAN and Bay Control are Automation units.
3. HMI/Control center level – consists of redundant data servers, operator’s workstations, engineering workstations, Local Area Network (LAN), printers and time system.
4. Remote data level – consists of gateway, routers and firewalls.

The entire substation will be monitored and controlled from Substation Control Room through independent substation computers and associated HMI, while individual circuit bays will be monitored and controlled from processor based Bay Control Units.

All configuration parameters and substation monitoring systems functions can be retrieved as if connected directly to the device, altered and then re-downloaded. A copy of the configuration can be maintained on the engineer’s workstation for future use.

Our substation automation solutions can be divided into two groups: Substation Control and Information Management System (SCIMS) and Distributed Control Systems (DCS).

DCS Solutions Represent of Intelligent Electronic Devices

DCS (Distribute Control System) solutions merge all communication capabilities of IEDs in a substation or across a network to perform a physically distributed logically integration protection, control, metering, monitoring and automation scheme. DCS solutions are tailored to eliminate much of the dedicated control wiring along with the special purpose communication channels. The data gathered by this system does not only consist of the data for control operation or in other words SCADA data, but also “non operational” data used in the future to operate the power system in innovative ways.

This new abundance of data can then be fed into an asset management program to monitor equipment and facilitate better maintenance decisions. DCS Solutions can use traditional legacy, IEC 61850, or a mix set of protocols to utilize the existing assets of the electrical network.

IEC 61850, it represents a major shift in how intelligent electronic devices (IEDs) communicate within the substation and beyond. Essentially, IEC 61850 replaces the physical copper wires linking IEDs together with virtual ones by way of an Ethernet network.

The transition to IEC 61850 is by no means a slam dunk. It represent a major shift in utility management and practice, and it requires a whole new set of skill on the part of the engineering professionals charged with making it work.

Substation Control & Information Management System (SCIMS)

The substation Control & Information System (SCIMS), form the basis for integrating all substation data including traditional SCADA data, protection data, IED data and support for substation automation sequences.

Due to its inherent capability to integrate multi vendor IEDs, the solution provides a mechanism for utilities to maximize their benefits from the existing IEDs deployed in the network and have greater bargaining power when purchasing IEDs. The system can be either centralized or consists of many fully integrated SCIMS cells. Each cell has the responsibility to collect data via hardwired or communication signals, transfer the data to the SCIMS cell responsible for master station communication and eventually send the data to one or more master or HMI stations.

The SCIMS is based on real-time operations, and includes the following functions:
• Real-time data for operational purposes.
• Configuration data for maintenance and network reconfiguration.
• One solution for multiple vendor IEDs / protection devices.
• Access to data other than through the traditional SCADA interfaces.
• Scalable – capable of handling from a single IED up to very large substations.
• Integration of newer IED which support Ethernet/TCP/IP Protocols.

In a recent installment, UIS has deployed a system concurrently running more than 10 different IEDs and various control center protocols.

PLC and DCS in PAC application

DCS systems have for many years provided multi-disciplined controllers for logic, sequential and process control, HMIs and applications on one platform. That’s the really definition of s DCS – an integrated, distributed systems approach. It’s more than just about the individual component being pulled together into one platform. It’s about the way data flows through the system, the way that information is presented to an operator, the way that changes propagate through the database, control strategy, graphics, applications, etc and the robustness of the platform as a single entity.

The impression is that some PLC companies are creating a great deal of hype over PACs, but customers who are familiar with a DCS are already aware of the concept. Customers that are doing side by side evaluations with PLCs are choosing the DCS. The PLC vendors still seem to be struggling with trying to get all the parts and pieces to work together seamlessly.

We believe this goes back to core competency and the primary domain in which a system was designed to work from the ground up.

The DCS has come a long way from proprietary, large systems of the past to being scalable to meet a wide range of applications. Most customers that have in the past used PLCs are delighted when they see what’s available to them today in current, state- of the art DCS solutions.

Automatic Gates using PLC Keyence

PLC Type KV-10(16) Keyence , Name Input / Output PLC :

INPUT PLC :
0000 ; Area Sensor 1.
0001 ; Area Sensor 2.
0002 ; Area Sensor 3.
0003 ; Area Sensor 4.
0004 ; Limit Switch for Open gate.
0005 ; Limit Switch for Closed gate.

OUTPUT PLC :
0500 ; Contactor for Electric Motor (Open Gate ).
0501 ; Contactor for Electric Motor (Close Gate ).

PLC Programming for Automatic Gates using PLC Keyence

Reading Ladder PLC Programming for Automatic Gates using PLC Keyence :

Step 1 :
Open Gate
a.If 0000 = OFF AND 0004 = OFF Then 1000 = ON (Hold ON).
b.If 1001 = ON AND 0001 = OFF OR 0002 = OFF Then 1003 = ON.
c.If 1000 = ON OR 1003 = OFF Then 0500 = ON.

Step 2 :
Close Gate
a.If 0004 = ON AND 0003 = OFF AND 0001 = ON AND 0002 = ON AND 1004 = OFF AND 0000 = ON Then 1001 = ON (Hold ON).
b.If 1001 = ON AND 0001 = ON AND 0002 = ON Then 1002 = ON.
c.If 1001 = ON AND 0001 = ON AND 0002 = ON AND 0005 = ON Then 1004 = ON AND 1001 = OFF.
d.If 1002 = ON Then 0501 = ON.

Please Download Programming for KV Builder :
Automatic Gates using PLC Keyence

See : Automatic Gates

The Best Applications for PLCs in Process Plant

The most appropriate application for PLCs in process plant is on the packaging lines where high speed discrete control and synchronized motor drives are required. The following can be used as a guideline for those who are considering PLCs on the process side:
• Future growth at the site- will the site is growing in size or scope? If so, it is much easier to expand DCS architecture than PLC architecture while still keeping one integrated control system.

• Need to make change frequently- Does the user need to modify control logic or graphic frequently? These tasks are easier to do with a DCS and can be done while the system is running so there’s no need to stop the controller to add new logic.

• Integration requirements- what are the needs around workflow of operators and control engineers? Do they need access to history, alarms, live trends, live view of control strategies, system diagnostics, etc? These are built in to Experian PKS environment. Also, integration of other systems (PLC, SCADA, etc), devices, applications the enterprise? These can all be more tightly integrated with a DCS and with less engineering.

• Robustness- PLC controllers are very robust, the concern is at the HMI/application/engineering layer. What is the tolerance for loss of view, loss of data, downtime associated with servers/HMI/applications?

• Network – What are the networking skills of the plant folks? Setup and configuration of the network are designed into Experian PKS as a part of plant network environment. Compatibility of various components are tracked and tested, patches are tracked and tested, etc, making the network maintenance load much simpler than a PLC system.

The Benefit of DCS on Configuration

One the provider of DCS is Honeywell. They have refined DCS solution and made it easy to configure with templates, engineering tools, application libraries and scenarios for specific process control applications. Configuration of DCS is better than programming. Configuration means that the logic and control scenarios already exist in the system as functions that are applied to the application. These functions are proven, tested and repeatable insuring high quality and low cost to maintain the system.

When configuring a tag, everything required is there to connect it to field point and alarm logic, history, version control and other functions, saving times and improving quality. You don’t have to build alarm logic, configure a separate historian and other functions.

Configuring field control is straight forward. For example, if you have two inputs, one output valve, there is a Function Block library so you don’t have to create the logic from scratch. Again, customers use proven and repeatable logic that improves quality, reliability and speed.

The control logic and flow is clearly visible during run-time using DCS approach in contrast to ladder logic where someone could have later added a rung or made a change in the logic that is not apparent. Because the logic connections flow are clearly visible in the DCS, making changes takes less time and there is significantly less risk of creating problems leading to higher process reliability.

Cost is a Factor to Choose PLC or DCS

In the past it was fairly easy to determine whether a PLC or a DCS was right for an application but in recent years this has become more difficult. It is argued that more powerful PLC product coupled with the new software tools provide an integrated process control system rivaling a Distributed Control System (DCS) for process control applications.

The architecture of a PLC and DCS system look strikingly similar on a system layout drawing with the same basic components: field devices, input/output modules, controllers, and Human Machine Interface (HMI).

Today with open technologies, DCS system are competitively priced with PLCs, in fact, if you consider the cost of implementing the system and the cost of making changes to the system over time, in addition to the initial purchase price, the DCS can be much less expensive. The total project costs include the expenses required to build a working solution that accomplishes the long-term goal of effective process control.

One must consider maintenance and changes to accommodate growth over time. These total costs are lower than applying PLCs because the built-in functions and inherent integration available in a DCS enable implementation and maintenance of a more effective system with less labor.

Checklist for Connected Operation with PLC

This checklist will help you create a plan for a connection session with the PLC. There are some items that can be as key points in the checklist:
• Determine essential parameters of the PLC.
Check that the project is appropriate for the PLC with which you will be working. Note any important characteristic of the PLC which may affect the connected environment (for example – memory, I/O setup).

• Establish the type of communications to be used
Make sure that your computer is correctly configured to communicate with the PLC, and that you have the necessary cables to make the connection.

• Check the project for accuracy and completeness
Use the program check feature for verifying your project and the networks it contains, and make softcopy of it, before making any changes while connected.

• Make a note of the appropriate I/O assignments
List all I/O devices and assignments to be made them, including the PLC I/O bit allocated to each.

• Establish PLC parameters
Use the Project PLS Setup command to set the appropriate environment in the PLC.

• Create a map for PLC memory area usage
Note the variables that your program uses, and where these can be found in PLC memory for monitoring.