All Activity

This stream auto-updates   

  1. Past Hour
  2. Today
  3. Thanks Michael, I plan to test it out tomorrow and hope the 5 breakpoints and the 2nd-order poly is accurate enough. much appreciated
  4. function generator or polynomial block in PLC5

    There was a post a few months ago, by a moderator, where he used Excel to do the same thing. I think it goes out to 5th order but I don’t have access to a computer right now (typing this in my phone, more than once :/ )
  5. MSG alternative to acees BOOL type data?

    Ok, then it’s easy, you can’t do that.
  6. Absolute addressing on AB PLC

    I’m not aware of anyway to see the level addressing that I think you want to see. Ie Tag Bool resides in some absolute memory address In the microprocessor and you want to see it.    Even Mel’s reference to Local: for IO isn’t the actual physical level address of the microprocessor IO. It’s just a pointer.    I think that knowing hardware level memory addressing would pose some level of security risk
  7. Thanks Mickey. Using the mycurvefit website, I was able to plot a 2nd order polynomial curve with five breakpoints, and then put the calculation into the CPT-compute instruction. Take a look at the pic, if you have time, and let me know if this is what you had in mind. Thanks!
  8. See link.. It is an online curve software to generate a formula for you. Then just use a compute instruction. https://mycurvefit.com/
  9. See link.. It is an online curve software to generate a formula for you. Then just use a compute instruction. https://mycurvefit.com/
  10. Thanks NevergoldMel. You are correct, the first curve was very linear, but this curve is more in line with actual characteristics. So, is there a way to create a poly in PLC5?
  11. I think you are a Modbus expert.

    I  need advice for communication modbus Tcp Fx5U to Fx5U

    Thank you.

  12. OMRON VS FACTORYTALK

    You probably don't I'd suggest a OPC server.
  13. why you set analog Output ?   You Can Setting Modbus RTU. Navigation>>>Parameter>>>Module Parameter>>>485 Serial Port >>Communication Protocol Type>>>>Modbus_RTU Communication
  14. Absolute addressing on AB PLC

    Local:
  15. function generator or polynomial block in PLC5

    With any margin of error that's a linear graph.
  16. The fear of FOR TO loops

    There's a reason QuickBASIC wasn't ported to windows.
  17. Prv instruction in structured text

    I've only used it for creating function blocks for alternate PID equations, odd pump curves, a rather odd pH vs flow equation, and such oddball things crazy P.E.'s come up with.  
  18. How can I create a function generator or polynomial in PLC5/80? By this I mean I need a eleven point curve that changes the output based on the input. I do this all the time with DCS logic, but I don't see a "Polynomial" of "Function" block in RSLogix5. A simple curve might look like this. input        output     x1=    0    ...y1=    0 x2=    10    ...y2=    31 x3=    20    ...y3=    58 x4=    30    ...y4=    89 x5=    40    ...y5=    118 x6=    50    ...y6=    147 x7=    60    ...y7=    178 x8=    70    ...y8=    216 x9=    80    ...y9=    238 x10=90    ...y10=   269 x11=100    ...y11= 300
  19. How can I create a function generator or polynomial in PLC5/80? By this I mean I need a eleven point curve that changes the output based on the input. I do this all the time with DCS logic, but I don't see a "Polynomial" of "Function" block in RSLogix5. A simple curve might look like this. input   output   x1= 0 y1= 0 x2= 10 y2= 20 x3= 20 y3= 31 x4= 30 y4= 49 x5= 40 y5= 59 x6= 50 y6= 79 x7= 60 y7= 101 x8= 70 y8= 142 x9= 80 y9= 178 x10= 90 y10= 224 x11= 100 y11= 300  
  20. How I open file bin ihm fuji UG 530h ?

    I need help, I want modification ihm fuji UG 530h , the upload file bin, I am use software VSF edit V6.0, but not open.
  21. Yesterday
  22. MSG alternative to acees BOOL type data?

    Michael, your suggestion violates the initial condition: reading a BOOL tag should not require in the target controller any preprogrammed procedure specific to the tag name. pcmccartney1, the same, plus the MSG instruction still will not support boolean datatype, arrayed or not.
  23. Good day. I'm using 1756 L71S GuardLogix Integrated Safety Controller with Studio 5000 v28. My controller is connected to a third party software through ethernet connection, it simulates my project hardware and provides all the signals to my PLC. To know all the hardware signallocation at PLC memory, it uses a Tag export file provided by Studio 5000. In other PLCs, when you declare a variable as hardware input, you have to select in which address from the memory you want this input to be read, something like "Bit Input 0.0". But in AB this step is skipped, that is all addresses are managed by Studio5000 and hidden from the user. Is there any configuration at Studio 5000 that let me assign or at least see this addresses? Normally I would prefer my tags addresses to be hidden, but in this specific case it is more useful to know memory addresses.  
  24. The fear of FOR TO loops

    The biggest objection I have to loops in the PLC is that they're harder to diagnose later. I would say if you're using loops, be meticulous and over-zealous in your documentation. Explain every detail of what you're doing and why so a technician on 3rd shift won't have any issues figuring it out 5 years from now. Without having to call an engineer. From a programming standpoint, just be careful when designing your loops to properly limit check them so you don't run past the end of your array. Most production managers don't have much of a sense of humor when it comes to faulting processors. Writing the loop is often simpler to avoid typos and copy-paste errors than having a rung for each element. If you have 40 items, it may not be a huge deal to have a rung for each, but when your array is a couple hundred or a thousand items, you almost have to do a loop just to stay sane. As an end user (not an OEM) who has to support the code in the long term, I will sacrifice memory/performance every time for ease of troubleshooting except in a few limited scenarios where the loop is doing something that's not critical to the machine's operation and that's unlikely to require diagnostics later. Like looping through alarm messages to display on an HMI. War story: we had a contractor come in and create a very complex piece of code for us that has multiple nested loops that are almost impossible to untangle. It works great...until something goes wonky and we have to download an old copy of the program into the PLC to get it working again. Power-cycling the PLC doesn't fix it. There's some tag value somewhere that makes it not work. After several years of it happening every few months, we're no closer to identifying the pattern. I spent several days one time just going through the code and making a flowchart but wasn't able to reproduce the bug. Weirdly enough, we have the identical code running in 3 lines in 3 different processors. One of them (originally a ControlLogix -L55M12 at v16 and now an -L81E at v30) has never gone wonky, another one (ControlLogix -L71, v24) goes wonky every other month or so, and the third (CompactLogix -L33ER, v24) has only gone wonky twice in 1.5 years or so. I've run comparison after comparison between the systems and haven't been able to figure out why that would be. In my opinion, loops definitely have their place, but PLEASE document them so I don't get a phone call at 3AM.
  25. Hi everybody,For a while I’ve been wondering, in every plc forum where the use of loops come to discussion I find most people answering that it’s best to stay away from them and that there are better, easier and mostly less scan time demanding solutions out there. Why is that?In my experience they’re the next best thing.Why would referencing data from an array of 40 Dwords using a FOR X:= 0 TO 40 DO loop be any more scan time demanding then the PLC scanning through 40 rungs of statments?Just curious if I’m missing something here. Cheers
  26. Prv instruction in structured text

    Oh and btw, thanks Michael,  reading A 270 as a DINT made me recieve some numbers
  27. Prv instruction in structured text

    Maybe it’s a European thing  Like Michael said, in certain cases it’s very useful. In my current project for example, I work with large amounts ascii strings and data set in Lwords, which need to be shifted or moved and referenced in various ways Also I have remote in- and outputs from 40 individual stations for which I use arrays and lots of FOR TO loops and CASE statements  to make things easier to implement en modify.  In my opinion, once you get the hang of it the possibilities are endless and it’s much less time consuming to write, especially when using loops.
  28. Load more activity