Together with the pH value, the redox voltage is one of the most frequent process variables in industrial and municipal effluent plants, as well as in installations for monitoring drinking water and bathing (swimming pool) water.10/30/2008
For reasons of hygiene, drinking water, or any other water that people come into direct or indirect contact with, often has to be treated with compounds that destroy any micro-organisms contained in it. Chlorine, chlorine compounds or ozone are very often used as disinfectants. In this sensitive area, a high level of safety for the consumer is an absolute requirement, and for this reason, systems are used for fully automatic monitoring, control and recording of the disinfectant concentration.
Amperometric sensors provide the best means of monitoring the disinfectant concentration. This technical publication will present the electrochemical fundamentals and the application technology of such sensors in an easily understood form, for the interested reader.10/30/2008
The methods of determination of hydrogen peroxide and PAA are not continuous measurements methods, but methods whereby the concentration is measured for samples taken at certain times.
These analytical methods are laboratory procedures requiring a considerable outlay in personnel and time.
In order to regulate the concentration of a disinfectant, it is advantageous if a electrical signal is available that is continuous and proportional to the concentration of disinfectant. This signal can then be used as the input signal for controlling a disinfectant metering system, i.e. the concentration can be completely automatically regulated.
A membrane-covered amperometric measuring cell can be used for monitoring the peracetic acid concentration and the concentration of hydrogen peroxide.10/30/2008
Measurement of the concentration of ammonia in aqueous solutions is a requirement in many application areas, such as for coolant monitoring and laboratory measurement. A fast and simple way of measuring ammonia can be achieved by using a membranecovered, gas-sensitive sensor that operates on a potentiometric principle.
But for successful measurement, several factors must be observed when handling and using of ammonia sensors. This brochure is intended to provide practical help for the users in these matters. A special emphasis is placed on the two application situations mentioned above.
Furthermore, the construction and mode of operation of the sensor is also briefly described.10/30/2008
The paper provides an in depth tutorial of how to help secure networks in production plants. Its recommendations are based on latest platform technology, current standards and WinCC and PCS 7 product features. It offers comprehensive coverage of security concepts and up-to-date detail documents that explore specific solutions and recommended configuration based on specific products or topics.10/27/2008
The "WinCC Security Concept" documentation contains recommended and mandatory procedures for planning and building secure, networked WinCC automation solutions with connected Web clients, SIMATIC IT applications and office networks based on customer specifications. This documentation serves as both a reference and a guide for network administrators working in the following areas:
- Configuration of WinCC
- Commissioning and servicing of WinCC
- Management of company networks
It is intended to facilitate cooperation.10/20/2008
Why is Lack of Interoperability in Wireless a Concern in Industrial Applications?
While the available potential for wireless deployment in factory automation is high, the adoption of wireless is plagued by various concerns surrounding the wireless technology, one of which is lack of interoperability. In the recent past, interoperability was not as major concern as it is currently. People predominantly used to build their own systems or purchased them from a single supplier. Increasing plant automation has spurred the demand for wireless devices and systems for numerous applications like monitoring, alarm and telemetry with a large number of suppliers offering these systems or solutions. They are often customized on proprietary protocols but not based on a common standard or architecture. As a result, these devices offered from multiple suppliers are not often compatible with one another. So even though the options have increased, the end users have become more concerned about the compatibility of the devices.10/08/2008
Analysis of the Mesh Topology in ISA100.11a D2.
Before a network can be used it must be formed. As part of this formation, devices must be provisioned with a network ID and a join key. The network ID is used to associate a device with a network and the join key is used to protect the device as well as the network during the join operation. Provisioning devices can be done by the manufacturer, in the maintenance shop, or in the field. In the D2 draft neither the requirements for nor the actual physical interface for provisioning has been specified.10/07/2008
The ISA100.11a D2 draft is a major step forward over D1. The D2 document is the first draft that attempts to be a full specification of the network and application protocols for process monitoring and control devices. However, it is incomplete.
The editors have done a substantial amount of work in generating the newest version of the specification. A large number of comments were reviewed, accepted, accepted in principal or otherwise incorporated into the document. In addition, new technical material was developed to fill in the technical omissions that existed in the old document. As a result, the D2 draft requires a thorough review.
In reviewing the document the first goal is to determine if the technical details meet the overall goals stablished for the standard. This paper considers the primary goal of a standard: the interoperability and interchangeability of products (Section 6.2). The intent of this paper is to provide the reader with objective information about the draft to enable them to determine if these goals are met and to assist them in providing comments to the ISA100 committee.09/25/2008
The white paper describes the hardware and software elements of a video process monitoring system, how it uses the plants industrial network to transmit video to the control system and how the video images appear on HMI screens.09/10/2008
Control editor Walt Boyes speaks to the TÜV Safety Symposium in Cologne. Read a transcript of his speech, "Warum Ist Sicherheit So Schwer?/Why Is Safety so HARD?09/02/2008
Business drivers to improve performance, such as supply chain performance and operational effectiveness, require that integration of Enterprise Resource Planning (ERP) and shop-floor systems is considered. Many manufacturing companies have implemented the SAP R/3 ERP system, supporting core business processes including financials, sales, distribution and so on. The manufacturing processes may be controlled by a combination of automatic control equipment and human operators. SAP R/3 supports production planning functionality in its PP (standard production planning) module and sub-modules PP-PI (production planning for the process industries), PP-REP (repetitive manufacturing) and PP-Kanban. These modules support the exchange of data with external systems. However, the technology issues associated with such data exchange are part of a broader set of challenges that an integration project must address if the intended business benefits are to be obtained. This paper examines a business-driven approach to integration and explores recent project experience integrating shop-floor systems with the PP and PP-PI modules.08/28/2008
One of the current problems of batch automation specialists, especially in the pharmaceutical industry, is the integration of PLC-controlled units (package units, e.g. centrifuges, dryers) into DCS-like control systems maintaining homogenous structure. On the basis of IEC 61512-1:1997 standard Workgroup 2 of Hungarian Batch Forum prepared a draft Proposal for users and manufacturers of package units that suggests different methods for the integration of package units. The paper discusses the integration from a system-architecture point of view while the communication problems of control equipment are not considered.08/28/2008
In the recent years, batch process optimization has made significant advances. The efforts that went into the development of ISA-S88/IEC 61512 batch control standard has helped us in this direction. However, in todays highly competitive environment, optimization of individual manufacturing plants is not enough. In order to maximize the return on investments, control engineers must turn their attentions to site and company wide optimization along with the optimization of the supply chains. Typically, batch processes use many different raw materials to produce various products and grades of products. Market demands require frequent changes in product mix under short notice. Thus, batch processes offers greater opportunities than typical continuous processes for the optimization of raw material and intermediate supplies, production scheduling, and upstream and downstream transportations. For the last five years, the ISA-SP95 committee has been developing the standards for integration of control systems with business systems. This effort is significantly helping site and company wide optimization of manufacturing processes. Additionally, the recent developments in Internet and intranet technologies are increasing the feasibility of supply chain optimization. Today, the challenge for control engineers is to broaden their focus from narrow control issues to wider aspects of enterprise-wide optimization.08/28/2008
Successful Contract Pharmaceutical Manufacturing in a GMP regulated environment is heavily dependent on the flexibility and utilisation of the available processing plant and its guaranteed performance. However, changing plant configuration and revalidation is time consuming and therefore costly. This paper presents a case study of the implementation of an S88.01 based control system, as part of a strategy to change an existing process building with single product manufacturing capability, to a multipurpose plant and contrasts it with an earlier retrofit implementation to a similar plant for multi-product use. The paper reviews some important considerations in the equipment model design including the design approach for the control system architecture and methodologies employed for software coding of generic phases, which have been found to yield real economic benefits and ensure the achievement of the required plant flexibility. It also reviews the benefits to the design and validation process from following a structured 'GAMP3' approach. Some of the measurable economic benefits achieved will be shown to include reduced project implementation time, life cycle cost savings through reduced manpower effort during the engineering and validation stages and production capacity increase.08/28/2008
Does your plant suffer from high software maintenance costs, inflexible batch production, safety and environmental regulatory pressures? The Ineos Acrylics Plant at Darwen in the UK was experiencing these problems which are experienced with many legacy batch control systems in the modern chemicals market. The problems can be overcome with an S88 compliant system and approach but the right structure is essential. Reviewing the problems and plans to replace the system it was clear that a simple migration of the existing system would achieve little and that a complete re-structuring based on S88 was required. It was anticipated that this would give economic benefits of reduced software maintenance costs, increased production flexibility, reduced environmental/safety risks, all of which were achieved and more besides. This paper describes the process, problems and achievements of the project.08/28/2008
The World Batch Forum was originally formed to support the S88 Batch Control standard. All forums since have related in some way to the published part of the standard (S88.01) or to other, generally related, work. The second planned part of the standard is now ready for release. This paper attempts to put that event in perspective in the context of the current status of an on-going effort.08/28/2008
In the early days of batch automation there was usually a central computer that controlled everything. This computer ran recipes, executed sequential logic, did data acquisition of process variables and also performed direct digital control (DDC) of analog and discrete devices. Since one computer did every thing from sequencing to DDC it was only natural to imbed the shutdown and safety logic into the batch sequential code that was running normal operations. And since one huge monolithic program ran the entire process, the safety logic was always running. In modern S88 (IEC61512) based modular batch automation systems the monolithic code has been replaced by smaller reusable phases controlled by a batch manager that runs recipes. Many who have grown up with DDC imbed safety logic inside the phases. This approach requires an active equipment phase at all times to keep safety logic available at all times. There is a problem with this approach. Phases are transient by nature. They have a beginning and an end. You cannot guarantee that there will always be an active equipment phase. Although there may be some holding logic associated only with a specific phase, often this logic is generic and should be moved up to the unit level. This paper looks at methods available to the user for safety and exception recovery logic in current modular batch systems. Included are case studies of five separate batch projects where recognizing exception conditions and executing safety shutdown logic was essential.08/28/2008
From which supplier ingredient lots did we compose this batch? Which batches did this pallet feed? Which batches ran after it? Whats the effect of this badly performing unit on previous operations? Whats the correlation between ? These are not easy questions, too often left without an answer. In many cases we have to rely on a combination of the operators memory, some paper log sheets and a variety of electronic data sources. With the introduction of the ISA S88.01 standard in 1995 and the work of the SP95 committee, process industries finally receives a structured framework that extends its advantages beyond the pure process control aspects. By applying the standard, we have a basis for building in traceability as an intrinsic function of the production control system. We will focus on topics like material flow control, the process inventory, integrating quality control and non-conformity checking in the batch recipe and building product genealogy. During the presentation we will explain the methodology behind this and how leading enterprises have already successfully applied it.08/28/2008
All of the components, and the zones in which they reside, that comprise the scope and magnitude of batch manufacturing have always been a challenge to fully comprehend at a single instant. When attempting to automate these components one must understand the unique requirements of the zone in which the component resides, as well as the touch points and interactions between the different S88.01 models. The approaches used to modularize and automate these touch points and interactions have a great impact upon the usability of the automation. The concepts of Unit Modes, Equipment Module and Phase residency are key to a usable automated batch manufacturing application. This paper explores the zones of batch manufacturing and an approach to automate the touch points and interactions of the S88.01 models that provides a very usable application.08/28/2008