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About pop29684

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  1. SIEMENS S7 200

    I think I understand what you are trying to accomplish: 1. Turn on a buzzer output for 3 seconds when a PB is pressed; buzzer must continue to sound for the full 3 second period even if the PB is released before the timeout period (3s). 2. Re-trigger the buzzer timer for another 3 seconds if the PB is released and pressed before the initial 3 second period has timed out. The solution is not readily seen because normally one would think that the trigger/re-trigger logic would apply only to the timer. This is not possible because an extended pulse timer cannot be re-triggered until it has timed out. A standard TON will not work because releasing the input PB before the timer has timed out will cause an immediate reset of the timer and the buzzer will turn off. However, a solution is possible: use a re-triggerable timer (TON) but latch the buzzer output directly from the PB press. Test the logic below. I think it will do what you wish. I don't have a 224 CPU to test. Let me know if this is what you are trying to do. EDIT 5 JULY 2019: I just tested this in the simulator. It works. Change the timer preset (PT) value to  300.
  2. Remote connection using eWon

    I've never used eWon but isn't that a Chinese product that connects to Chinese servers? Given the uncertainty of their security, I would suggest using Siemens Sinema.

    Analysis: the integer value stored in VB50 (decimal "1") is sent to the 7-segment display (QB5) when bits M0.3 AND M17.1 are both true (high, ON, 1). The 7-segment display must see segments b and c both equal 1; all other segments must equal 0. The S7-200 manual (p325) shows the relationship between the integer value to be displayed and the corresponding segments that must be ON for the correct value to be seen on the 7-segment display. The 7 segments are ordered from "a" to "-", with segment "a" being the LSB of the byte and "-" being the MSB of the byte. In the network example you provided, only integers 1, 2, 3, 4, and 0 are displayed on the 7-segment display. These integer values can be directly converted to a decimal value that will turn on the corresponding segments of the 7-segment display. The resulting code is shown below. It is a direct replacement of your network 76 without inventing a module to act as the "SEG" instruction. Nice, quick, simple, and easy. Just what the doctor ordered! :) Edit 18 June 2019: The absence of the "SEG" instruction for the 12## series CPUs is not due to the TIA Portal programming software. Rather it is because of the CPU (hardware) you are working with. The "SEG" instruction is available in TIA Portal when working with 15## and 3## series CPUs. I suspect the instruction is also available for the 4## series CPUs but I cannot confirm this because I don't have any current projects in TIA Portal that use this series of hardware.  The TIA Portal software only allows access to instructions compatible with the hardware you are programming.  
  4. Controlling Cylinder Stroke Length

    1. How is the cylinder actuated: pneumatic, hydraulic, electrically driven? 2. How is position being determined?
  5. How to replace a safety output card (1734-OB8S)?

    What makes you suspect the card is defective?
  6. problem with keyence

    If the program has been set to read protect you will not be able to upload the program from the CPU into the KV LadderBuilder software. I seem to remember, however, that you can still go onlline and monitor. It's been a long time since I've dabbled with the Keyence KV series and I don't have one handy with which to test my recollection. I've never used the Keyence Backup Tool software so I can't help you in any way with that. If you have hardcopy (printout) of the PLC program, search through it for the MEMSW instruction. This is the instruction that enables/disables read and write protection of the PLC program (and a number of other things, also). This instruction is detailed in volume three of the "User's Manual". The discussion begins on page 3-92. If you do not have a manual it is available from the dowload section of this site.
  7. Pop up login screen editing

    What PB press on the screen causes the pop-up? I would look at the programming of that PB. It could be directly programmed, use a script, macro, or something similar.
  8. How can I do a simple sequence step delay

    I've given a little more thought to your question and I think I have a single-network solution that will work for you. As you can see, this compiled without any errors. The difference is the use of the "isolation" condition, in this case "mLog1" (an "Always True", "ATI", or similar name). The N.O. contact shown could just as easily be replaced with an N.C. contact of "tStep_Dwell.Q". The effect of using the timer done bit would be to make the network execution function as a one-shot. Also note the absence of an output instruction on the "Q" output of the timer. This logic was designed in TIA v12.  
  9. How can I do a simple sequence step delay

    Hmmmmmm. I went to the Siemens forum and found an item that discusses this very issue. It is dated from 04 NOV 2011. Here is the link (https://support.industry.siemens.com/cs/document/54684852/in-step-7-(tia-portal)-why-is-it-not-possible-to-branch-to-a-move-instruction-for-the-s7-300-400-before-the-in-parameters-of-the-iec-timers-counters-?dti=0&lc=en-WW) but I don't know if you will be able to view it without signing in to an account or not. It is free to create an account and there is a lot of good information there. The article shows two different IEC timer functions, one with "EN/ENO" connections and one without. I don't want to copy and paste the information here because I don't want to infringe any copyrights. I would highly recommend creating an account just to view the discussion. In the mean time, the bottom line is that you were able to resolve the issue. Maybe not the way you would have liked or the way you are used to, but you've made it work. Good job!
  10. How can I do a simple sequence step delay

    I see in your initial post an error message relating to the use of an IEC timer. The TON is an IEC timer. What was the complete message? What did you do to resolve the error?
  11. How can I do a simple sequence step delay

    What is your frustration? Do neither forms work? I've used both successfully, although I prefer the second. Does TIA require the placeholder output instruction?
  12. Siemems Set Reset with singal input

    Another variation of Travis' logic can be found here: http://forums.mrplc.com/index.php?/files/file/1073-fc2-toggle-a-bit/. The logic uses two rungs but does not need the (S) and (R) instructions.
  13. PE Exam

    JRoss, I think we agree on the bottom line. A qualified PE is valuable. Taking the PE exam and passing it is an important notch to have in one's belt, so to speak. And I have clearly, and repeatedly said that there is nothing wrong with pursuing such a notable achievement. I was taking exception with what I perceived was an expression that seemed (to me) to be careless and incompletely thought out. So let me reiterate one more time - there is nothing wrong with pursuing, holding, or hiring a qualified PE. The original  question was whether one should pursue taking the exam. My answer is unequivocal - yes. But I have offered a caveat - don't assume that just because a person holds a valid PE certification that they are capable. This is the reason we have review boards - to investigate allegations of incapacity and wrong-doing. If every engineer holding a valid PE certificate was unquestionably qualified and capable, then such review boards would not be necessary. I think I have quite clearly enunciated my thoughts and position. I do not wish to continue this debate.
  14. PE Exam

    JRoss, you are correct. And every medical doctor must satisfactorily complete a residency/internship before given their own shingle to hang out for their own independent practice. This residency/internship includes supervision and mentoring from "seasoned" medical professionals. But I'm sure you recognize that there are doctors who have completed the requirements but whose skills are questionable. Or maybe their business practices are questionable. Or there could be other factors involved that could impair their judgement and/or practices. The point I am making is that the key is not to *exclusively* nor *blindly* trust any test - including the PE exam. I don't care who the PE in question is, I'm going to do my own research and try to determine to *my* satisfaction that the engineer is credible, capable, and has an impeccable reputation. For example, I certainly don't want to hire someone who has a history of litigation, no matter how incredible their skills are; I don't want such a history to potentially drag me into a similar mess. And of course, there is the question of cost. We all know that cost is usually one of the biggest - if not the biggest - factors in any business equation. So you might have incredible skills for which you think you should be able to command a premium price for. But how good are those skills if your potential client opts to hire another PE for half or three-quarters of your cost, and whose skills are not as polished as yours? Let me return to the original question. Yes, pursue the license. It could open doors for you that would never otherwise open. Just remember that the PE exam, like any other exam, only proves that you were capable of  passing the exam on the day of the exam, and under the conditions existent during that time period. It is not predictive. Let me affirm one more time, I'm not against the exam. Or any exam, for that matter. They are devices widely accepted - and necessary - for ranking knowledge, skills, etc. Just keep in mind that there will always be other factors to include in your considerations, and in your client's considerations. And *no* test or certification should ever be the sole factor in any decision-making process.
  15. PE Exam

    Sorry, but not valid reasoning, in my opinion. Not trying to flame anyone. But I've worked with many people who couldn't pass an exam to save their life. But could do outstanding work. I've also worked with others that were the exact opposite - could ace a test any day of the week under any conditions but couldn't perform worth squat. Don't misunderstand me - I'm not against tests. But realize that tests are not to be blindly trusted as the most accurate indicator of a person's ability to perform quality work. Just as correlation does not always equal causation. One must understand the context, not just the end result. It is like writing a PLC program. I can teach any breathing being to write a program to make a machine move. But can they do it safely? Simply? Efficiently? In a way easily understood by anyone else? I would guess that perhaps you have never hired or relied on the services of someone else based on a high recommendation or qualifying credentials - only to personally experience less than satisfactory service. It does happen.