In the process of equipment automation upgrades, replacing I/O connections is often considered one of the most basic equipment upgrades. Internal I/O systems can reduce the inconvenience caused by replacing I/O connections between the manufacturing process and the control system. Moreover, in some cases, the I/O system can even become the control system itself. A major I/O upgrade is usually due to a lack of replacement parts, where the user needs to increase performance or expand functionality, and the old system cannot meet the user's requirements. Upgrading the I/O system may also be for "reducing costs and enhancing overall reliability and durability," says Bill Griffith, Product Manager for GE Fanus CNC. I/O system upgrades can enhance the user's competitiveness to help their business grow. Tom Edwards, Senior Applications Engineer at Opto 22, says that replacing I/O may be due to changing vendors, complying with company requirements, cost-effectiveness, or upgrading the network from a serial-based industrial network to Ethernet (which offers higher speeds, more communication options, and other advantages) and adding connections at a higher density. Basic I/O system functions include data acquisition, wireless communication, and compatibility with PC systems. [align=center]Figure 1: A brewery bottling line is equipped with I/O module connections, allowing for rapid modifications to the end effector (robotic gripper) as required by the application. This flexibility cannot be achieved with physical wiring connections. Edwards explains that customers should review their vendor's change history and plan ahead before upgrading I/O to avoid replacing/removing all modules, brackets, sensors, actuators, and wiring. Having more feasible options provides more choices. He also cautioned against signing long-term contracts for maintenance, service, and technical support unless absolutely necessary. Chuck Greene, from Digital Coating Device's product department, said that the scope of an I/O system upgrade should be defined beforehand. While process engineers upgrading built-in I/O systems may not need to consider overall system availability, OEMs providing industrial-grade controllers may prioritize system availability, including factors such as the fieldbus model, I/O area, applicability, and operator importance. Using products from the same supplier for I/O upgrades offers many advantages, facilitating strategy transfer, new product technology transfer, and the seamless integration of hardware and software tools in process production. Robb Dussault, manager at Schneider Electric, said, "Using this firsthand information saves development and installation time, component costs, and most importantly, reduces risk." Dussault also pointed out that developing new product lines may lead to incompatibility. Furthermore, companies need to assess whether to migrate all technology, a portion of it, or only a part of it to determine the best approach for optimal performance. Dussault said that to choose the best migration method, it's crucial to consider the impact of both short-term and long-term investments on long-term benefits and cost savings. Helge Hornis, manager of Pepperl+Fuchs Intelligent-systems, mentioned that generally, existing I/O connections (devices) should only be replaced when all other methods fail. He suggested that this provides flexibility, enhanced security, and the performance offered by other digital networks and module connections. I/O technology implementation clarifies the theory behind enterprise replacement or upgrades. Hornis explained that robots can handle various commands from different end-user manipulators (grippers). Users operate the same robot to perform different tasks. On a flexible filling line, using an AS-interface digital network and different I/O connection devices, the gripper can quickly switch tasks while powered on. AS-interface networks offer this flexibility, which hardware writing cannot achieve. Artomation painting equipment In developing a more powerful new human-machine interface, Artomation, a company that manufactures automated painting equipment, redesigned its product I/O system. Mr. Greene of Artomation said, "Our advantage lies in the scalability, versatility, and reasonable price of our products." He explained that the old system was an industrial PC based on the UNIX real-time operating system. I/O cards were installed on the PC (ISA or PCI) bus. This ensured fast and reliable communication. Adding new I/O cards did not require recompiling the code. However, Greene added that each I/O card could only add one I/O point, and each card required an interface board for connection. Both of these factors increased system costs. More importantly, a PC failure would cause the system to crash. Therefore, the redesign focused on programming the distributed I/O components (according to the IEC 61131 standard) to achieve independent operation without PC dependence. While baseboard PLCs are powerful, reliable, and versatile, implementing I/O expansion with them presents significant challenges. Mr. Greene explained that choosing a large baseboard increases project costs. Using alternative I/O modules requires reconfiguration of the ladder logic, necessitating additional programming and code recompilation. Greene stated that Artomation uses a combined PLC and Wago (750-842) programmable area bus couplers. The baseboard saves space. All products can be equipped with any configuration, such as various digital and analog models, as well as special modules (e.g., RS-485, high-speed counters), simplifying specifications and reducing design time. Expanding I/O capabilities requires no additional configuration at the PLC level. Greene says that the continuous development of HMI tools has simplified system configuration and simulation calibration, reducing outsourcing time by 30%-40%. The system is equipped with overload protection, AD/DC onboard power supply, and overload monitoring, thus improving diagnostic capabilities. Modules in the plug-in bus can be inserted and removed without tools, saving downtime. I/O point expansion can be achieved without interface boards, costing only one-tenth of the cost of PC (I/O point expansion). Dussault says that, for example, Schneider Electric and SAB worked together in Gauteng, South Africa, on a phased migration program. SAB used a phased migration approach, initially replacing only the front-end Modicon processor, and then gradually updating all I/O connection devices. Ultimately, this enabled a comprehensive overhaul of the control system during 24/7 uninterrupted operation. [align=center] Figure 2: PanelPro automatic coating machines can be configured differently according to customer needs. Any Wago digital, analog, or dedicated module can be added as needed without a PLC. Figure 3: The Wago (750-842) programmable fieldbus coupler has a small baseplate, working with Artomation When the equipment is in use, it can save panel space. Figure 4: Schneider Electric Modicon 800 series I/O modules allow users to replace the entire rack at once, rather than just a single component, which effectively reduces installation time and cost. Figure 5: Chevron uses Opto 22 AITM-8 thermocouple modules with wired connections. Refining Technology Due to the need for more connections, Chevron recently updated its I/O modules. (This project) was conducted in Chevron's laboratory in Richmond, CA, where the company adopted Opto 22's new Snpa AITM-8 channel thermocouple I/O modules. Technicians and scientists in the laboratory are experimenting with catalysts to induce the decomposition of natural petroleum and enhance refining technology. The Snap-AITM-8 module has eight channels to receive temperature input or millivolt inputs from various standard thermocouples. Chevron requires connections to numerous thermocouples that act as process variable inputs, which are used in PID loops to regulate temperature during testing. The new module significantly increases the number of access points, four times that of the previous two-channel device. This results in a substantial return on investment and reduces the cost per I/O point. Chevron is equipped with nearly 12 I/O racks, each with 12 eight-channel AITM-8 thermocouple modules, resulting in 96 connections per rack. Colonial Efficiency Some engineers believe that centralized I/O architectures can cost up to 75% more than distributed architectures due to installation and maintenance difficulties. However, despite this, many companies, including the Colonial Group, still seek to avoid wired connections. For 80 years, Colonial's raw material handling systems have used centralized control platforms. Today, however, the theory of better and more efficient cost utilization is gaining increasing popularity, and Colonial is a proponent of this theory, gradually shifting its production in this direction. Before I/O migration, the first problem to solve is… Schneider Electric Telemecanique Automation and Control Robb Dussault, Head of Services, reminds equipment administrators to answer the following questions before upgrading I/O devices: ■ What initial investment do we want now and in the future? ■ How long can we tolerate system downtime? ■ Do we need to change vendors or retain our existing automation control system provider? Dussault suggests that, generally speaking, if a company plans to upgrade the entire system while minimizing initial investment and downtime, phased migration is the best option. He adds that phased migration uses a multi-step approximation method, and the upgrade may take several months or even years, while minimizing the impact on production processes. Regarding fixing I/O vulnerabilities , Jerry Penick, a control engineer at Rockwell Automation, suggests that when upgrading a control system, replacing the I/O system usually means rearranging the existing area wiring and dealing with years of "panel vulnerabilities." Penick explains that this is why engineers typically reserve I/O system replacement as a last resort, provided it remains within budget and the existing I/O system can function properly. However, upgrading I/O connectivity offers numerous benefits, such as network upgrades, increased speeds, and the ability to connect more new I/O devices. To ensure success, a well-developed plan and thorough documentation are essential before undertaking projects like this. Penick says, “Plan downtime effectively and ensure sufficient replacement time to cleanly and efficiently install the I/O backplane.” He adds, “If time is limited, add I/O components in the vicinity or install new ‘distributed I/O’ in available space on the existing backplane to ensure system operation during the upgrade.” “To avoid numerous panel rat traps, install distributed I/O as close as possible to sensors and actuators—using current network technology for information exchange—rather than outdated centralized panels.” To ensure a smooth upgrade of (old and new) I/O devices, Rockwell Automation recommends: ■ Examine and document the current wiring configuration; ■ Install the new I/O system before changing the wiring layout to verify the new network connectivity and "remove" the new I/O terminal components; ■ Inquire with the vendor about the specific details of the junction boxes and swing-arm adapters to understand how to integrate the new I/O modules into the existing wiring layout. This simplifies the entire upgrade process. ■ Installing small "distributed I/O" units in a nearby area can save installation space and time, and also shorten disassembly time. Founded in 1921 and headquartered in Savannah, Georgia, the company supplies a wide range of goods to manufacturers worldwide, including dry and liquid products, and provides products such as kaolin and petroleum to various industries globally, including paper, automotive, and agriculture. Its plant, located on over 300 acres along the Savannah River, produces millions of tons of dry and liquid products annually. Colonial recently pointed out that their centralized raw material handling structure was not functioning effectively. Besides the problem of frequent installations and maintenance, plant management was unable to collect equipment information or manage diagnostics. This resulted in data loss and hindered overall production efficiency. To address these shortcomings, Colonial redesigned a raw material handling system for new equipment called Georgia Kaolin Terminals (GKT). As the name suggests, GKT is a system for producing kaolin, a mineral abundant in Georgia. After processing, this material can be used in the paper, rubber, and coatings industries. After installing the new distributed GKT system, Colonial reduced installation costs by 15% and achieved real-time diagnostics. The system can obtain information from various frequency drives, motor controllers, I/O modules, and Rockwell Automation smart devices to make diagnostics.