Industrial Automation

Condition monitoring

by


Condition monitoring is the process of monitoring a parameter of condition in machinery, in order to identify a significant change which is indicative of a developing fault. It is a major component of predictive maintenance.

Availability of advanced electronics and software in powerful instrumentation, computers and digital signal processors has simplified and extended our ability to control and analyse machinery. Automated systems allow continuous condition monitoring of certain critical items of plants. Significant benefits can be derived from applied monitoring. Measurement and control systems allow early alarming avoids unplanned downtime of machinery and equipment. We can achieve greater plant efficiency by reducing losses due to breakdown and replacement costs.

Critical machines that should have a high availability need to be monitored continually but we need to figure out a way of deciding which parameters should we monitor.
The parameters to be monitored are essentially those that affect operations and maintenance scheduling. Currents and voltages, coolant temperatures, bearing vibration levels, have been measured and will continue to be used. Generally speaking; before some period of time from breakdown, energy consumption of the machine increases. Such patterns can be discovered by machine learning and by further analysis of data but for the sake of the article we are only focusing the first phase, condition monitoring.

Notice that we monitor our equipment ,monitor the condition to preserve and or prevent catastrophic failure. This is great because breakdowns can be frustrating. But condition monitoring doesn’t improve reliability on its own. Improving reliability involves taking a proactive approach and considering root causes of the problem.

All in all,wearing multiple hats and changing perspective will help us make us of condition monitoring excellently. If you like the article and follow up our industrial iot articles you can navigate from Industrial Iot Dictionary

HMI HUMAN-MACHINE INTERFACE

by


HMI is short for human machine interface. They are also referred to as touchscreen operator panels in the market.

We use HMIS and industry to control and monitor machines. It would be hard to have a good automated process in industry without an HMI.

We can operate the machine from the HMI. The screen and push buttons (physical or virtual) allow us to operate the machines. We can also monitor the machine statuses, process steps, material counts etc via HMI screen.

Comparing analog indicators, HMIs show very precise levels and exact positioning of machines where machine information used to be viewed on multiple indicators. On one digital screen almost unlimited (software limited) indicators are possibile.

HMIS connect to PLC to control and monitor near real time data. HMIs are also used to load recipes to PLCs. Compared to connecting a computer or laptop every time, HMIs can save valuable time.

Another benefit of having a modern HMI is the fact that plants can monitor and control multiple machines or sensors with a single hmi. Small manufacturing facilities could even monitor the entire plant with a couple of HMIs located centrally.

HMIs and PLC’s work together to monitor and control the machine. This means they have to be compatible and they also have to speak the same language. They do this on what’s called a protocol. Different companies use different protocols such as PROFIBUS and PROFINET.Protocol information is found on each manufacturers website.

HMIS use special software so engineers can program them correctly. Different brands of panels use different software.

Those specific software allow the engineer to design what the operator will actually see on the screen what they can monitor on the screen what buttons can be pushed and how the operator can manipulate the machine for.

PLC Programmable logic controller

by

Today I am going to talk about the basics of a PLCs, the brain of industrial automation.

The programmable logic controller or PLC is a special-purpose computer that is hidden in the control panel of most machines.

The plc was a replacement for panels of relay devices that turn on and off machine.

The cons of relay logic control forced industry innovate PLCs. Making a machine run using relays as logic was time-consuming and challenging. Making a change in the logic or the operation of the machine was almost as complicated as starting over. Relays also fail far more frequently than computer components so that relay logic required more downtime to keep it running. Controls based on relays use a lot of electricity make lots of heat and sound and take up lots of space.

An installed PLC looks pretty simple. In appearance you have a CPU module and input/output devices referred to as IO. Sometimes the IO is part of the CPU and sometimes it is in other modules. in some equipment the i/o modules can be miles away from the CPU and connected with data cables so that the PLC is not limited to a single cabinet or even same room.
Since the plc is a computer there is no need to limit it to only digital inputs and outputs. To make these numerical devices more useful, manufacturers added analog and other numerical inputs and outputs to these devices over the years.

Plcs have calculation capability in the programming as well so that we can now calculate for instance statistical process control or SPC values and put PID controllers directly into the PLC program

As the name programmable logic controller suggest we need to program it. Most PLC’s are programmed using an application running on a PC. These specific applications communicate with the PLC using Ethernet/IP , Modbus or similar communication bus depending on the manufacturer.

Most manufacturers seem to have settled on Ethernet and/or USB in recent years but unfortunately the PLC manufacturers have failed to agree on how we program the control logic.
We have several choices when it comes to choosing a brand of plc depending on where you work you may have to familiarize yourself with many different plc brands. Some places use more than one manufacturer in a single facility so let’s list some of the major brands down so we can see the difference. Probably the biggest names out there in the automation and PLC world is Siemens, Rockwell, Allen Bradley, ABB, Omron, Mitsubishi, Schneider and Delta.