TILI Automation

 PLC and DCS are two different types of control systems that are used in industrial automation applications. While both systems are used to control and monitor industrial processes, they have some important differences in terms of their design, function, and application. Design: PLCs are designed as standalone controllers that can be used to control a single machine or process. They are typically used for discrete control applications, such as controlling motors, sensors, and other devices in a manufacturing process. DCS, on the other hand, are designed as distributed control systems that can be used to control and monitor multiple processes or machines across an entire plant or facility. They are typically used for process control applications, such as controlling temperature, pressure, and flow in a chemical plant or oil refinery. Function: PLCs are typically used for discrete control applications, where the process involves discrete events or steps, such as moving a conveyor bel...

 Annunciator Panel is a device that consists of a number of visible signals such as “flags” or lamps indicating the status of an alarm system or systems. Each circuit is usually labeled to identify the location and condition being monitored. In addition to the visible signal, an audible signal is usually associated with the device. When an alarm condition is reported, a signal is indicated visibly, audibly, or both. The visible signal is generally maintained until reset either manually or automatically. An annunciator panel is a group of lights used as a central indicator of status of equipment or systems in an industrial process, building or other installation. Usually, the annunciator panel includes a main warning lamp or audible signal to draw the attention of operating personnel to the annunciator panel for abnormal events or condition. Annunciator Panel Process control In industrial process control, an annunciator panel is a system to alert operators of alarm conditions in the...

 DCS are used to control production systems within the same geographic location for industries such as oil refineries, water and wastewater treatment, electric power generation plants, chemical manufacturing plants, automotive production, and pharmaceutical processing facilities. These systems are usually process control or discrete part control systems. DCS are integrated as a control architecture containing a supervisory level of control overseeing multiple, integrated sub-systems that are responsible for controlling the details of a localized process. A DCS uses a centralized supervisory control loop to mediate a group of localized controllers that share the overall tasks of carrying out an entire production process. Product and process control are usually achieved by deploying feedback or feedforward control loops whereby the key product and/or process conditions are automatically maintained around the desired set point. To accomplish the desired product and/or process toleranc...

 In general, spares in the control system (PLC or DCS) are defined as consumable spares, commissioning spares, installed spares, 2 years operational spares, and mandatory spares. Control System Spares Consumable spares and commissioning spares Consumable spares and commissioning spares are normally recommended by the system vendor supplier. These spares are meant to be consumed before the system is fully operational and these are required to avoid using any of the recommended operational spares. These spares are ordered along with main items. For instance, Fuses, terminals, relays, printer cartridges, A3/A4 papers, and so on. Installed spares Installed spares as the name indicate, are installed within the control system. These spares are utilized when there is the failure of a component within the system so by using installed spare; the system is operational without any downtime. The requirement of installed spare shall be defined as part of the project scope. Assume if one channel...

 This is mostly known to everyone that a square root Function is required for Orifice Flow Transmitter as the relationship of flow versus pressure is not linear but has a square-root relationship. But the next question is? where should you do this square-root function? In Transmitter or DCS or both or none? Note: we can do this square root function in two ways. one using the physical device called square-root extractor and this is an old method. Second is using the software configuration either in transmitter or in DCS. Here we are discussing the second method. Interface issue between System and field instrument engineer. The first point of caution is the proper interface between the requisition (field) engineers and system engineers. Sometimes the engineer purchasing transmitter assumes it will be done in DCS. While the system engineer assumes it will be done in Transmitter. And NOBODY does it. Similarly, the converse is also true. The Square-root extraction is done at both places...

 A sensor is an input device that provides a usable output in response to the input measurand. A sensor is also commonly called a sensing element, primary sensor, or primary detector. The measurand is the physical parameter to be measured. An input transducer produces an electrical output that is representative of the input measurand. Its output is conditioned and ready for use by the receiving electronics like PLC or DCS. The receiving electronics can be an indicator, controller, computer, PLC, DCS etc. The term “transmitter,” as commonly used with industrial process control instrumentation, has a more narrow definition than those of a sensor or transducer: 4-20 mA Transmitter A transmitter is a transducer that responds to a measured variable by means of a sensing element and converts it to a standardized transmission signal (like 4-20mA) that is a function only of the measured variable. Transmitters can have any of several electrical connection schemes. The most common and easiest...

 PLC or DCS System ? The following steps discuss about How to choose PLC or DCS systems ? Step 1: Does process require implementation of advanced process control (APC)? No doubt, the vast majority of process control applications can be handled sufficiently with traditional regulatory control using proportional-integral-derivative (PID) technique, or by combining it with other traditional regulatory control functions, such as feedforward, cascade, split range, and ratio control. Yet, as industrial process plants keep demanding higher levels of stability and minimization of process variability, especially for control problems involving multivariables and long process delays, the need for APC techniques, such as neural network, adaptive tuning, model predictive control, and others is growing steadily. DCS manufacturers have been leading the way in integrating APC functionalities into their systems, while PLCs are limited to traditional control methods. And so, if a process demands one...

 DCS are used to control production systems within the same geographic location for industries such as oil refineries, water and wastewater treatment, electric power generation plants, chemical manufacturing plants, automotive production, and pharmaceutical processing facilities. These systems are usually process control or discrete part control systems. DCS are integrated as a control architecture containing a supervisory level of control overseeing multiple, integrated sub-systems that are responsible for controlling the details of a localized process. A DCS uses a centralized supervisory control loop to mediate a group of localized controllers that share the overall tasks of carrying out an entire production process. Product and process control are usually achieved by deploying feedback or feedforward control loops whereby the key product and/or process conditions are automatically maintained around the desired set point. Also Read: What is DCS System? To accomplish the desired ...

  Physical Checks All civil works required for  DCS cabinet  installation shall be completed. Ensure painting work is completed in the area. Ensure completion of false flooring in the area, if applicable Ensure proper lighting available in the control room and Panel Room. Ensure  HVAC  is commissioned for the area or ensure proper ventilation in the area. Ensure proper installation and fixing of the panels at the location as per GA drawing. Check and ensure anti-vibration pads of the panels are in place. Check that dust filter on louvers is clean, for indoor panels Check DCS panels for the physical damage – Door lock, door limit switch, Fans, Tube lights, internal cables, MCBs, isolators, modules, racks, controllers, prefab cables, etc. Check all the components of the panel as per BOM. Check for loose supplied items. Check and verify all hardware like Engineering and operator station as per BOM. Pre-Requisites Ensure availability of approved DCS GA drawings,...