Entries for the 'Automation' Category

DMC is working with Panasonic to provide power consumption feedback for industrial machinery. If a piece of equipment is going to consume thousands of dollars of electricity each year, isn't it worth keeping tabs on it? Panasonic's line of low-cost industrial power meters provide instantaneous and totalized power consumption information to your existing SCADA system through a multi-drop RS485 interface. Or you can add Panasonic's own data collection and reporting server for out-of...

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Eric Nielsen’s Real Time blog did a good job of hitting the major strengths and benefits of any system based on a controller running a Real-time operating system. Here I’ll get into a little more depth, specifically for the capabilities these systems give in regards to distributed execution. As we’ve learned, the major benefits of running a Real-Time system are determinism and robust operation. These benefits can be realized in a very powerful way: distributed execution. Dis...

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Kermit the Frog once sang, “It’s Not Easy Being Green.” Sorry Kermit, we at DMC disagree - it's actually pretty easy. We know “going green” is trendy right now, but it’s something DMC has focused on for awhile. It does take a concerted effort, but whether it’s in our office or in our industry we're contributing to a greener planet on Earth Day and every day. At DMC we strive to be eco-conscious as we deliver world-class solutions for our clien...

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One of our many areas of expertise at DMC is developing and integrating machine vision systems. Our focus is on offering the most effective solution for the application; we are hardware/vendor independent and are not tied to any platform. When selecting a vision hardware and software platform, the most important questions to answer are: What are the technical challenges of the application? How many vision systems will be produced? How many cameras are needed for each vision system? I...

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Siemens and Rockwell Automation are two giants competing in industrial automation technology today. Rockwell (aka Allen-Bradley) seems to be more popular in the US market, but Siemens has a larger international customer base. A cursory Google search will reveal that there is no lack of debate among automation professionals over which one is preferred. On the higher end of their PLC lines, the programming environments to use are: Siemens - Step 7 Simatic Manager for S7-300 and 400 level ...

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In many industries, shaftless drive technology has replaced the old mechanical drive systems. Instead of using mechanical gearing to force one axis on a machine to follow another one, servos are used. The servo technology reduces many of the flaws of a large mechanical gearing system as well as provides a lot of flexibility. This technology is in heavy use in industries such as the automotive, packaging, and printing. Using the shaftless drive technology requires the use of a motion controlle...

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Since their conception PLC programs have been founded on simple programs. RLL (Relay Ladder Logic) and IL (Instruction List) commands have dominated PLC programs since PLCs first came to market in the 1970s. However in the past few years automation requirements have grown more complex and demanding. This has in turn led to PLC manufacturers beginning to include some higher level programming concepts in their software packages. What exactly have they added? And what does it mean for your manufact...

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The concept of LabVIEW Object Oriented Programming (LVOOP) has been around for a number of years now, but has consistently been one of those areas that seemed to have to high of a learning curve to justify learning “just because”. Luckily, in a recent project I managed to get the green light for implementing an object oriented (OO) solution. For me the biggest appeal for OO programming in LabVIEW was the increase in organization, manageability, and code-reuse that it offers. The i...

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When commissioning or troubleshooting PLC inputs and outputs (IO), the analog signals are often the most difficult. First, analog IO almost always has to be scaled to convert the raw signal to useful process values. Also, there are many wiring and external device (sensor/actuator) configurations. Here are some simple guidelines for troubleshooting and working with Analog IO. Although these guidelines are intended to help you think about the process of troubleshooting, this process will surely...

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We are frequently asked to work on PLC systems for clients that we did not develop. The job could be troubleshooting an issue or adding a new feature to the system. Working with unfamiliar code has its own unique challenges, although we take pride in our ability to do so. Here are some things you should keep in mind when asking an integrator or even your own internal maintenance staff to take a look at your PLC system. Source Code Almost every PLC system I've worked with does not store...

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For those of us who appreciate and harness the power of indirect addressing in Siemens S7 300 and 400 level PLCs, we were sad to hear that this functionality was not supported in the same way for the new Step 7 Basic software for S7-1200 PLCs. As of Service Pack 2 for Step 7 Basic 10.5, however, Siemens has added array indexing functions that get you closer to indirect addressing. They are called "FieldRead" and "FieldWrite". Essentially, they are functions that allow you ...

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Many consumers, including myself, have tapped into the ever-growing functionality of mobile internet. Many people leverage this infrastructure for their mobile phone. Others are beginning to use WiMAX connections for their PCs. Not to be out-done, PLCs are also capable of communicating through wireless data plans. DMC just finished the proof-of-concept phase in a project using the new Siemens Simatic S7-1200 PLC and Siemens Sinaut MD720 GPRS GSM cellular modem. We were able to successfully se...

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DMC has been involved in quite a few battery testing projects lately. We thought it would be helpful to assemble a compilation of some of the general things we have learned into a new white paper.... "Electric Vehicle Battery Pack Testing in a Manufacturing Environment" If you are interested in the automotive battery packs used in electric vehicles (EVs), hybrid electric vehicles (HEVs), and plugin hybrid electric vehicles (PHEVs) and how they are tested, this article should cont...

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While developing a Windows PC based long term test system running LabVIEW software, we found the use of Norton Ghost to be a very effective means of setting up multiple identical test stand units quickly and efficiently. Basically we took the approach used all the time by IT dept. system administrators and applied it to customized test system development. Having a stored hard drive image of the original state of each test station also proved to be a useful "restore" point to use to res...

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We have added a few new Case Studies that showcase two of the business areas in which we recently have had a number of projects: Sharepoint Development and Battery Testing. Check out these Case Study entries to read more detail! Sharepoint Timesheet Entry Portal Battery Management System (BMS) Validation Test Stand Battery Pack Monitor System for Environmental Testing

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DMC started as a motion integrator (the M stands for motion). Even though we do a great many other things these days, we still maintain a strong competency in this area. We were recently contacted by a client who has an old Acroloop 2000 ISA based motion controller running on a Windows NT with 32MB of RAM. Their concern was that parts to repair this legacy motion equipment would be difficult to obtain and could result in undesired downtime. We set out to find the best way to update this appli...

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There are certain control systems, such as in nuclear power plants and airplanes, that cannot be disabled or shut down, even momentarily, because of the threat to people’s lives. In these applications, a redundant control system must be in place to take over instantaneously if the primary system fails. I recently deployed one such redundant control system for train tunnel ventilation at a major international airport. The system's main objective is to control, reduce, and help exting...

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When choosing a piece of hardware, you will likely be confronted with many options from different vendors for what interface (PCI, PXI, USB, Serial/GPIB, LXI) that device will use to communicate with your software controller, so how do you choose? USB devices are often significantly cheaper than their PCI or PXI counterparts, but this reduced cost comes with a trade-off in the overall stability and robustness of the communications interface. Windows background operations in PC based systems, ...

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Encapsulating your data into custom Data Structures will allow you to Dominate (maybe not the world, but at least your PLC) I'm going to conclude my series on the IEC 61131-3 standard by examining the benefits of Data Structures. (If you missed my other posts, you can check out the previous part 1, part 2, part 3) Before we dive into Data Structures, let's review basic data types. Every PLC supports a certain group of standard data types. The list typically includes the followin...

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Ever wanted to use those very nice looking Siemens touchpad HMIs with a third party controller Siemens doesn't officially support? On a recent project I was presented with the following scenario: a customer already had several Siemens touch-screen HMIs in stock, and wanted to use one to help operators control an Elau motion controller. Of course to do this I had to get the HMI and controller to talk to one another. The HMI understood about 20 different protocols — everything from Allen...

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