Top PDF Introduction to Programmable Logic Controllers

Introduction to Programmable Logic Controllers

Introduction to Programmable Logic Controllers

Topics covered will include exploring what a PLC is, operation, usage, instructions, applications, hardware selection and configuration, introductory programming examples and exercises, and some troubleshooting hints. The accompanying lab manual will give the student hands-on programming and hookup exercises. Students will configure different PLCs, set up the RSLinx drivers to communicate from a personal computer to the PLC, select proper modules, and calculate power supply loading. A lab exercise will walk students through a motor starter interface to an SLC 500 PLC along with issues in converting conventional ladder start-stop into PLC logic, separation of I/O, and proper instruction selection. Programming exercises will provide hands-on experience developing simple programs that incorporate basic instructions up to and including timers, counters, and sequencers.
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Programmable Logic Controllers and Ladder Logic

Programmable Logic Controllers and Ladder Logic

Introduction Subject Programmable logic controllers (PLCs) have become the most predominant control elements for the discrete event control of a mechatronics system. Simplification of engineering and precise control of manufacturing process can result in significant cost savings. The most cost-effective way which can pay big dividends in the long run is flexible automation; a planned approach towards integrated control systems. It requires a conscious effort on the part of plant managers and engineers to identify areas where automation can result in better deployment and/or utilization of human resources and savings in man-hours or down time. Controls automation need not be high ended and extremely sophisticated; it is the phased, step-by-step effort to automate, employing control systems tailored to one’s specific requirements that achieves the most attractive results. This is where programmable logic controls have been a breakthrough in the field of automation and control techniques. This report looks at the role PLCs play in these techniques.
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A Building-Block Approach to Industrial Controls Laboratories Using Programmable Logic Controllers

A Building-Block Approach to Industrial Controls Laboratories Using Programmable Logic Controllers

A common career path for Electrical Engineering Technology (EET) students is the design and maintenance of industrial control systems. These industrial controls are typically designed using Programmable Logic Controllers (PLC) to execute and monitor the machine or process. PLCs are equipped with discrete and analog control of high and low current AC and DC voltages, and can also include PID control algorithms for closed-loop control structures. 2 Our University includes a total of twelve credit hours of courses to study the selection of control systems components and the overall system design; introduction, PLC-specific controls, and process control and automation.
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Programmable Logic Controllers

Programmable Logic Controllers

Jackson Lecture 3-15 Electrical & Computer Engineering. PLC simulator usage[r]

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Enhanced and Ethernet PLC-5 Programmable Controllers

Enhanced and Ethernet PLC-5 Programmable Controllers

Appendix C Maximizing System Performance Using This Chapter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-1 Program Scan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-1 Effects of False Logic versus True Logic on Logic Scan Time. . C-2 Effects of Different Input States on Logic Scan Time . . . . . . . . C-2 Effects of Different Instructions on Logic Scan Time . . . . . . . . C-3 Effects of Using Interrupts on Logic Scan Time . . . . . . . . . . . . . C-3 Effects of Housekeeping Time . . . . . . . . . . . . . . . . . . . . . . . . . . . C-4 Editing While in Remote Run Mode . . . . . . . . . . . . . . . . . . . . . . C-4 Putting Block-Transfer Modules in Controller-Resident Chassis C-5 Using Global Status Flag Files . . . . . . . . . . . . . . . . . . . . . . . . . . . C-5 Calculating Throughput. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-5 Input and Output Modules Delay . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-6 I/O Backplane Transfer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-6 Remote I/O Scan Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-6 Communication Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-7 Number of Rack Entries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-7 Block-Transfers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-8 Calculating Worst-Case Remote I/O Scan Time . . . . . . . . . . . . . C-9 Optimizing Remote I/O Scan Time. . . . . . . . . . . . . . . . . . . . . . . C-9 Controller Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-11 Example Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-12 Performance Effects of Online Operations . . . . . . . . . . . . . . . . . . . C-12 Effect of Inserting Ladder Rungs at the 56K-word Limit . . . . . . . . C-13 Using Program Control Instructions. . . . . . . . . . . . . . . . . . . . . . . . . C-14 Using JMP/LBL Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . C-14 Using FOR/NXT Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . C-14 Appendix D
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SIMATIC. Automation System S7-400H Fault-tolerant Systems. Preface, Contents. Fault-Tolerant Programmable Logic Controllers 1

SIMATIC. Automation System S7-400H Fault-tolerant Systems. Preface, Contents. Fault-Tolerant Programmable Logic Controllers 1

Figures 1-1 Operating objectives of redundant programmable logic controllers . . . . . 1-2 1-2 Totally integrated automation solutions with SIMATIC . . . . . . . . . . . . . . . . . 1-4 1-3 Example of redundancy in a network without error . . . . . . . . . . . . . . . . . . . 1-5 1-4 Example of redundancy in a 1-of-2 system with error . . . . . . . . . . . . . . . . . 1-5 1-5 Example of redundancy in a 1-of-2 system with total failure . . . . . . . . . . . 1-6 2-1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2 2-2 Hardware of the S7-400H base system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3 2-3 User documentation for redundant systems . . . . . . . . . . . . . . . . . . . . . . . . . 2-9 3-1 Hardware configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3 4-1 Layout of the control and display elements of CPU 414-4H/417-4H . . . . . 4-2 4-2 Positions of the mode selector switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-12 4-3 Design of the memory card . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-16 5-1 Diagnostics with CPU 41xH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-8 5-2 Diagnostics addresses for the DP master and DP slave . . . . . . . . . . . . . . 5-9 6-1 Synchronizing the subsystems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-3 6-2 System and operating modes of the redundant system . . . . . . . . . . . . . . . 6-6 7-1 Sequence of coupling and update operations . . . . . . . . . . . . . . . . . . . . . . . . 7-5 7-2 Sequence of update operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-6 7-3 Example of minimum signal duration at an input signal during the update 7-7 7-4 Meaning of the times relevant for updates . . . . . . . . . . . . . . . . . . . . . . . . . . 7-18 7-5 Relationship between the minimum I/O retention time
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Programmable Logic Controllers

Programmable Logic Controllers

The main components of a PLC are input modules, a Central Processing Unit (CPU), and output modules. A variety of digital or analog signals are accepted from various field devices by the input module. They are then converted into a logic signal that the CPU can use. The program instructions stored in the memory form the basis upon which the CPU makes decisions. These decisions eventually result in execution of the control instructions as required by the program. Control instructions from the CPU are converted into a digital or analog signal by the output module. This signal can be used to control various field devices. A PLC works by scrutinizing a program, instruction by instruction, continuously. This process is also known as scanning. One scan time is defined as the time taken to complete the three steps. The control loop is a continuous cycle of the PLC reading inputs, solving the ladder logic, and then changing the outputs. [9]
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Programmable Logic Controllers

Programmable Logic Controllers

AS-Interface SmartRelay SmartRelay AS-Interface Output Data Bit D0 Input In Output Qm Input Data Bit D0 Output Data Bit D1 Input In+1 Output Qm+1 Input Data Bit D1 Output Data Bit D2 Inp[r]

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DETEL SERIAL DATA TRANSMISSION PROTOCOL FOR THE COMMUNICATION OF AN IBM-PC WITH THE MDxx SERIES OF PROGRAMMABLE LOGIC CONTROLLERS Mustafa Dülger

DETEL SERIAL DATA TRANSMISSION PROTOCOL FOR THE COMMUNICATION OF AN IBM-PC WITH THE MDxx SERIES OF PROGRAMMABLE LOGIC CONTROLLERS Mustafa Dülger

The serial data transmission between two communicating electronic devices needs a certain data transmission protocol so that both agents of the transmission clearly understand each other. A typical master-slave system connected by a serial cable (i.e. RS232) is shown in Fig.1. The master device is an IBM-PC and the slave device is a Programmable Logic Controller, PLC, of type MDxx series [1]. The master sends a telegram to the slave. The slave should interpret the received telegram and operate accordingly.

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Effect of ESD on complex programmable logic device and field programmable gate arrays

Effect of ESD on complex programmable logic device and field programmable gate arrays

Keywords— System level ESD, FPGA, CPLD, Complex electronics, Indirect discharge, Direct Air/Contact discharge I. Introduction Electrostatic Discharge (ESD) is generally recognized as an increasingly important issue for modern integrated circuits. Thin- ner gate oxides, complex chips with multiple power supplies and/ or mixed-signal blocks, larger chip capacitance and faster circuit operation [1-4] all contribute to increased ESD sensitivity of advanced semiconductor products. For instance, you may find that a serial port IC has an ESD withstand voltage of 15KV! By the same token, a Complex Programmable Logic Device (CPLD) and Field Programmable Gate Arrays (FPGA) on the same circuit board have an ESD withstand voltage of only 75 volts!! Knowing that operators can easily generate up to (and exceed) 10kV, the ESD sensitive CPLD and FPGA [5] can be partially destroyed by an operator who is simply not following proper ESD control guide- lines. As ESD can occur anywhere from the receiving stage of your operations, to testing, manufacturing, shipping, and field han- dling of circuit boards & components, it becomes essential to study the effects of ESD so as to minimize the risk of ESD damage. As IC manufacturers move to smaller geometries, they continue to scale the dimensions of the transistors, interconnections, and the silicon layers in their devices. This decrease results in smaller architectures for higher-speed devices that are more susceptible
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pco sistema programmable controllers Technology & Evolution

pco sistema programmable controllers Technology & Evolution

Aria is a terminal designed for room installation, featuring a temperature sensor and an optional humidity sensor. Aria can be connected to the pLAN serial network for all versions of the pCO series controllers. In this configuration, the instrument measures the temperature and humidity of the room, sends this information by serial line to the machine’s controller (pCO), which based on the information received from the other zone terminals, decides the operating logic. Aria can also manage local dampers for effective zone-by-zone control.

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101 BASICS SERIES LEARNING MODULE 24: PROGRAMMABLE LOGIC CONTROLLERS (PLCS) Cutler-Hammer

101 BASICS SERIES LEARNING MODULE 24: PROGRAMMABLE LOGIC CONTROLLERS (PLCS) Cutler-Hammer

Communications abilities began to appear around 1973. The PLC could now talk to other PLCs and could be far away from the machine it was controlling. Because PLCs could also now be used to send and receive varying voltages, they were able to enter the analog world. But despite these advances, lack of standardization coupled with continually changing technology still made PLC communications a nightmare of incompatible protocols and physical networks. The 80s, however, saw an attempt to standardize communications. PLCs also got smaller in size and became software programmable through symbolic programming on personal computers (previously, PLCs had required dedicated programming terminals or handheld programmers). Today, the world's smallest PLC is about the size of a single control relay!
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The Advantages of Programmable Logic Courses

The Advantages of Programmable Logic Courses

At UNM, the first digital logic course is ECE 238L (Computer Logic Design). Its main topics include Boolean algebra and logic gates, combinational and sequential circuit design and analysis, and an introduction to computer design. There are several text books that cover these topics, (i.e. [28-32]). ECE 238L is based on [29] which covers these topics in the first ten chapters. Topics are supplemented by laboratory sessions where students gain practice by using actual hardware and learn the details involved in the design of digital systems.
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MAX+PLUS II. Introduction. Programmable Logic Development System & Software

MAX+PLUS II. Introduction. Programmable Logic Development System & Software

The Logic Synthesizer module in the MAX+PLUS II Compiler supports numerous synthesis options. It selects appropriate logic reduction algorithms to minimize and remove redundant logic, ensuring that the device logic resources are used as efficiently as possible for the target device architecture. It also removes unused logic from the project. Logic synthesis options help the designer guide the outcome of logic synthesis. Altera provides three “ready-made” synthesis styles that specify the settings for multiple logic synthesis options. The designer can choose a default style to set default synthesis options, create custom styles, and specify individual synthesis options on selected logic
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Introduction to Programmable Logic Devices. John Coughlan RAL Technology Department Detector & Electronics Division

Introduction to Programmable Logic Devices. John Coughlan RAL Technology Department Detector & Electronics Division

Fabric also has Larger Memory Blocks Block SRAM useful for Data storage And other “Hard Wired” logic blocks Eg CPUs, Memory Controllers….. Programmable Routing[r]

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Firmware Counterfeiting and Modification Attacks on Programmable Logic Controllers

Firmware Counterfeiting and Modification Attacks on Programmable Logic Controllers

circuit. However, many challenges remain in this area of research. Not only is a trusted baseline required for comparison, but the possible implementations of malicious logic are so numerous and complex that choosing appropriate detection metrics is difficult. Presenting a comprehensive approach, Baldwin et al. explore the issue of supply chain trust from a strategic perspective and propose new policies to integrate “system security engineering” into the current Department of Defense acquisition life cycle [7]. This proposal follows a cradle-to-grave approach to security. Pre-development planning focuses on security from the start by analyzing possible vulnerabilities of system components. Supply chain risk management is discussed and encompasses various techniques to minimize the threat of supply chain compromise. For critical components, a full scope supply chain analysis is performed to identify all suppliers involved with component production. The concept of trusted suppliers is introduced where strict requirements are imposed for such vendors. The purchasing of components should also follow diverse redundancy and anonymous buyer practices to minimize the probability of compromise. System testing focuses specifically on critical components as they interact with the rest of the system as well as many other non-hardware based secure design practices throughout the system life cycle.
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Programmable Logic Controllers Intro

Programmable Logic Controllers Intro

32 10. The FX family of PLC’s is designed to include a flexible range of communication options. State the main difference between the FX2-40AP and the FX-323AW interface adapters. The FX2-40AP is a parallel link adaptor used in applications where two machines are to have their operation synchronized. The FX232-AW is a serial interface that allows computers or inteligent machine interfaces to be connected to the programming port of all FX controllers. Both units provide full isolation by means of opto isolators on the communication lines protecting against over voltage. The main difference in terms of feature is that the FX-232AW is able to manipulate modems as it has an automatic carrier detect facility, meaningthat when it is dialling out through a modem it can detect when the telephone line connection is made. This makes modem communications quick, easy and more efficient. 11. Describe how two machines can have their operation sychronised or co-ordinated using PLC’s and FX2-40AP units
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Firmware Modification Analysis in Programmable Logic Controllers

Firmware Modification Analysis in Programmable Logic Controllers

the FMAT and the ARM disassembler, and provides the needed foundation for dynamic analysis. 6.3.5 Dynamic Firmware Modification Analysis. The static di fferences in code were made readily apparent, but analysis of the semantic di fferences is left to the analyst to evaluate. Dynamic analysis is needed to understand the semantics of firmware modification. A scenario is proposed to build a test case for determining behavioral di fferences between a suspect and base firmware. First a specific ICS system must be selected and engineered to specification, unless it is able to be simulated through software means. A working PLC base firmware and ladder logic program is chosen based on the scenario and data is then collected which captures the time and states of the PLC and the devices attached to it. The system under test would be the dynamic firmware modification analyzer which records a baseline pattern of static and dynamic data. Later an attack firmware and identical ladder logic program is recorded and then analyzed by the dynamic firmware modification analyzer to detect the dynamic changes made to the firmware. The dynamic firmware modification analyzer coupled with the static firmware analyzer create a picture which is compared for syntax and semantic differences. This would address the shortfalls of the static analysis and provide an automated approach for understanding semantic behavior differences. Additional information regarding semantic and dynamic analysis is discussed in Christodorescu et
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Programmable Fieldbus Controllers

Programmable Fieldbus Controllers

-Power jumper contacts This controller can accommodate up to two KNX logic devices at the same time. • 1. In conjunction with the WAGO-I/O-SYSTEM, the KNX IP Controller is used as a user-programmable application controller within KNX IP networks. The control- ler supports all digital, analog and specialty modules found within the 750/753 Series. The IEC 61131-3 programmable controller is capable of 10/100 Mbit/ s data rates. KNX objects of any type (EIS/DPT) can be created using the pro- gramming tool. Libraries including pre-made function blocks are readily available on the WAGO Web site for programming. The controller supports a maximum of 253 communication objects, as well as 254 group addresses and associations. • 2. Combined with the KNX/EIB/TP1 Module, the 750-889 KNX IP Controller
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WeaselBoard: Zero-Day Exploit Detection for Programmable Logic Controllers

WeaselBoard: Zero-Day Exploit Detection for Programmable Logic Controllers

Two adapter boards were created that enable the WeaselBoard to work with the Allen Bradley Control Logix 5000 and Siemens S7-300 PLCs. The Allen Bradley adapter board converts the logic levels of the data pins on the backplane to those used by the SmartFusion, and connects to the 24V power pins provided by the backplane. The Allen Bradley backplane has 32 data lines, 16 of these lines appear to contain framing data and the other 16 are a parallel data bus. The Siemens S7-300 backplane has two buses: an RS-485 serial bus, and a proprietary synchronous serial bus. The Siemens S7-300 adapter board provides logic level conversion of the synchronous serial bus and an RS-485 to RS-232 converter and connections to the 5V power lines in the backplane.
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