Beginning PLC programming [closed] - plc

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Closed 10 years ago.
I'm getting interested in PLC programming and my idea is to just try it. Therefore I need to simulate some real system, because it's to soon to look for some hardware. This is how I wish to do it (example):
Simulate some real system, ie. water tank with bleed and inlet valves, some water level sensor of course. These are controled and checked by PLC.
PLC simulator to control valves and get values from sensor. Also send data to some HMI/SCADA (PLCsim ?)
Some software to program the logic into PLC. (Step7 ?)
Some GUI for end user to check values and control valves manually (InTouch ?, ControlWeb ?, WinCC ?, LabView ?)
I don't know if this is possible completely by using software and if there is a chance it will work. Your advices and ideas are appreciated.
Thanks

Definitely. If money is an issue, AutomationDirect.com has a new product called Do-more where the programming software is free (called Designer) and it comes with a free PLC simulator.
I would then recommend writing separate code-block(s) to simulate "the process", where the code-block(s) READ from Outputs (discrete and analog) and WRITE to Inputs (discrete and analog) based on the Output states (and time, and random external events - think butterfly effect).
Disclosure: I work for Host Engineering, developers of Do-more.
If money is NOT an issue, I know there are lots of PLC Simulators and Process Simulator software out there that somebody can probably recommend.

Related

Phased Array System ToolBox. Overview [closed]

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Closed 9 years ago.
I have a requirement where in I need to simulate a radar in real time. I am yet to start with Phased array system toolbox (waiting for evaluation license), but I had few questions about the this toolbox. It will be really helpful if you can answer them.
Does the tool box supports real time simulation
Support for the environment. What environmental factors it takes into consideration.
Support for fluctuating RCS.
Support for tracking the targets.
Support for transponder and skin modes.
I will start with the study once I get my hands on the toolbox but till then any inputs here will be greatly appreciated.
Phased Array System Toolbox is a very niche product, and I doubt you'll find much experience with it available on StackOverflow. Even within MathWorks there are only a handful of people who know anything about it.
Nevertheless, I would recommend that the best (in fact only) way to find out any details of it would be to contact MathWorks directly. If you'd rather not contact them via Sales yet, you can contact John Zhao, the Phased Array System Toolbox Technical Expert (one of the handful described above) directly via the product's Contact The Expert page.
I can tell you that since it is a System Toolbox, it will be providing much of its functionality via System Objects, which are typically designed to support real-time code generation when used together with MATLAB Coder. I have no idea about your questions 2-5.

PJSIP and FreeRTOS [closed]

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Closed 9 years ago.
I have been investigating the use of the PJSIP SIP stack on a small micro-controller such as the PIC32 MCU and I've come to realise that it may just be possible. I want only the absolute minimal SIP functionality so I just might be able to fit PJSIP on a small MCU. Of course, it's a VERY ambitious project but I'm gonna give it a try anyway. I just can't seem to wrap my mind around the right operating system for use so I'm gonna spend a good couple weeks on this subject. I'm gonna take a look at FreeRTOS. Any thoughts on the compatibility of FreeRTOS with something like PJSIP?
I think the project site itself answers your question:
On portability
On Size
The memory resources suggested would be at the upper end for most on-chip memory. The RTOS's listed are all significantly more fully featured than FreeRTOS which provides little more than thread scheduling, timer services, synchronisation and IPC. You'd need to understand what OS services it assumes. Presumably it uses the platform's network stack? FreeRTOS has no network stack - you'd have to provide that too - more resources again.

Writing an operating system for arm architecture [closed]

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Closed 10 years ago.
How do I get started writing an operating system that runs on the arm architecture? I want to write a bootloader if possible and my own kernel. Can anyone help me get started?
I'd start by familiarising yourself with what is already out there - Linux is a good start. Look at the bootloaders used in the distributions on the rPi - what is used in Debian Squeeze for example, uBoot and BareBox. Another option is CFE - which is under BSD license and good during debugging/early development.
Another thing is to look at the ucLinux and ucLibC systems, along with buildroot and OpenWRT - all designed to squeeze it onto a small system.
Of course - building your own kernel - you are going to want to go far deeper - and spend time understanding MMU's, process management/multitasking, interrupts and so on. A good background in programming microcontrollers, a knowledge of assembler language and CPU/SOC architecture would be essential. With the ARM family - you'll want to know the various instruction sets supported, and which chips have features like MMU's, FPU's and similar.
Good luck - it sounds like an interesting project.

iPhone App - Coffee Cup Recognition [closed]

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Closed 11 years ago.
I want to build an iOS application that recognizes patterns in a cup of coffee.
For example http://en.wikipedia.org/wiki/File:Coffereading.jpg .
This image recognition script could run on the client side (iphone eventually) or on server side.
The goal of the app is to take a picture of a cup of coffee, analyse patterns,
and compare them with images/patterns that are already stored in a database, and return the most appropriate one
I have no experience in this field and after doing some research, I found some libraries that might help me do this: openCV, kooaba, snaptell, and server side libraries like afroge.net.
This confused me alot. I want to know if this is possible using libraries like the ones above, or any other one. And how much time/effort should be given if any modification should be made on one of those in order to achieve my goal
You can also read more information about reading fortune under this link: http://en.wikipedia.org/wiki/Tasseography
In short: It can be done with OpenCV. You can use it to recognize the coffee cup (circle and/or square detection). After that you have to take a look at "feature detection" (SURF ist a good way to go) to match the coffee patterns.
Yes, it can be done. But it's a huge topic and very complex.
Your best bet is to license third party code that will handle all the difficulties for you.
Take a look at this library available for iOS by Mataio:
metaio | Software | Augmented Reality 3

What is an Operating System (with respect to embedded systems)? [closed]

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Closed 11 years ago.
I have seen Operating Systems described as "the software that controls the hardware". I don't understand what it really is however.
For example, if we are writing code for a calculator, if we write the code to implement the interface between the LCD and KEYPAD, that code is not considered an operating system is it?
what really does "Operating System" mean?
Jack, the wikipedia page on operating systems gives a pretty good overview to start with. To put it pretty simply, when you want to run multiple pieces of software on a single piece of hardware (in your case, the ARM chip) then something needs to control the access to the hardware. The operating system will schedule tasks and allocate hardware to allow the multiple different bits of software to co-exist peacfully. Without this control, there is no way to run multiple pieces of software at once. Your calculator example would not require an operating system, as it is a single piece of code to do a single job.
For compilers for the ARM devices, I would suggest looking at either GCC (which I believe can cross compile to ARM) or getting a development kit, which will likely come with a suite of tools to allow you to develop on it.
I'm afraid I can't help you on which version of ARM chips to choose though, as my experience with them is a little limited. If price of the hardware is an issue though, I believe the ARM 7 hardware will be cheaper, but it is always worth comparing.
Hope this helps.