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Vidmas30

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Everything posted by Vidmas30

  1. Hello, Thank you for the answers! The idea to read 7 registers and etc is good, but the question was not how to make a shortcuts or workarounds, but about the principle: is my ladder code bad and what may be the reason of such behavior.. I did't get a chance to test code with dealys so far, but maybe until next week I do. Thank you!
  2. Thank you, Ofir, I'll try it and will post the results!
  3. Hi, Ofir, Thanks for quick reply! No, they're not consecutive. Their addresses are: Register1 - 3120, Register2 - 3122, Register3 - 3124, Register4 - 3126. And about delay: is there any sense to do delay? I think the bit conditions allow to read next register, only when previous been read? Or I understand not good?
  4. Hi, everybody, We are having application where V120 connected through RS485 (port 1) to powermeter using Modbus RTU. We made in our program that PLC gets data from power meter (4 registers) 2 times in a day. I wanted to ask if someone could advice or maybe has a simple example how to do data request of these 4 registers. We done in that way: Data request MB1 MB2 ------[P]----------(S) MB2 MB0(function in progress) MB2 -----[ ]-----------[ / ]--------------------------------[Read holding register 1]----------( R ) MB2 MB3 ------[N]----------(S) MB3 MB0(function in progress) MB3 -----[ ]-----------[ / ]--------------------------------[Read holding register 2]----------( R ) MB3 MB4 ------[N]----------(S) MB4 MB0(function in progress) MB4 -----[ ]-----------[ / ]--------------------------------[Read holding register 3]----------( R ) MB4 MB5 MB1 ------[N]----------(S)----------( R ) MB5 MB0(function in progress) MB5 -----[ ]-----------[ / ]--------------------------------[Read holding register 4]----------( R ) At the beginning it works fine, but there are issues: data does'nt change couple days, then changes or we get answers not from all registers.. I mean we not always get data. Maybe we are doing something wrong. Thank you for your help!
  5. Thank you, Emil, we are using 1 socket at each PLC, so 3 others are idle. So will do as you advice. That's what happens when you have to finish a job that someone started and not finished.. Thank you once again!
  6. Good day, Emil, The problem is that , as I mentioned, the cables were installed not by us. That happened because company didn't know what protocol will be used. There are spare cables installed and there is possibility to get daisy chain. I think we will try it because to change cables is almost imposible. By the way there are ETHERNET cards installed in all PLC's, but we are using them for communication with other devices. If there will be problems we will install switches/hubs and will be using ETHERNET. As Joe Tauser said: it's not really clear in the Unitronics documentation what topology should be used.. There's shown parallel connection of all devices (which can be in star topology) and no word mentioned about daisy chain.. Thank you for your quick help! VS
  7. Hello, everybody! Happy NEW YEAR! And now about our problem.. We have a net of 3 PLC's and monitoring computer with SCADA. All the PLC's controll various processes in their controll rooms and exchanging data with SCADA computer. All PLC's connected with each other CANbus net and because 1st controll room is near, we used serial connection to connect it to SCADA computer, where OPC server is ran and wonderware SCADA. In attached picture you can see topology we made. All cables are 5e cat. FTP cables (it was not our choise-other company made installation). In PLC's with ID 1 and 3 we put EOL resistors on CANbus connection. On each PLC's power-up we store id numbers to SI8 and initialize CANbus (ISC) with 100kb baud rate. PROBLEM: at first and for some time thereis no problem: data exchanging goes fast and good (data exchange is made every 2sec). But after some time, computer looses PLC of control room 3. Sometimes data exchange is restored (after some time) sometimes not. Sometimes computer looses PLC of control room 1 or 2. At first we thought it is because of cable length and changed the CANbus baud rate to 50kb (to all PLC's). But problem still occurs.. Maybe it's because there are used FTP cables?.. Please, it would be nice if someone could share his oppinion about CANbus network. THANK YOU!
  8. Ash and Damian, Thank you a lot for explanations it helps a lot. As soon as I'll do test on the field, I'll post results. Thank you once more!
  9. Hi, Damian, Link to manual is in my post above (sorry, but available only in russian)..
  10. Hi, Ofir, Since I can't attach manual (pdf) in this post, here's a link to instruction manual: http://193.17.84.244/pdf/controls_sup_sup-exh_AHUs_ru.pdf In the end of manual, there's a table with MODBUS TCP/IP data.
  11. Hi, Like Emil said, during autotune system gathers some essential data about process and gives a good starting point to manual tuning. So, I tried all methods (plc's (vision) autotune, pid server's autotune and end up with manual tuning) and I am quiet happy with the results! It's worth to try just for knowing what it is.. Thank you for your oppinion!
  12. Hi, As I mentioned, It's ventilation system controller, that has MODBUS TCP/IP port for data exchange. And that part of table is from instruction manual of that controller (yes, in my topic above I forgot to write that these are MODBUS TCP/IP register addresses of that controller). Oh, and the table I tried to write collapsed:) I'll try once more in other way: 1information register (r / w) : "scope" object link (0x2301'Unit1\SplyFanSpv.St1Spv'); connection to object element (0x0100); register address(9); description (0..100%). So, if connection to object is 0x0100 and register address is 9, then my START OF VECTOR in modbus tcp/ip should be 109(hex) ->265(dec). I don't know if I understand this part right..
  13. Good day, Started new project, where I need to connect with my V350-35-TU24 to ventilation system regulator to read some register and to control speed (remote). In it's manual described : 1information register (r / w): _______________________________________________________________________ | "scope" object link | connection to object element | register address | description | |___________________|________________________|_______________|___________| | 0x2301'Unit1\SplyFan- | 0x0100 | 9 | (0..100%) | | Spv.St1Spv' | | | | |___________________|________________________|_______________|___________| The same way are described all registers. Since I'm doing this first time, I don't know if I'm doing this right way (addressing): If I want to read register, then in Uni Vision I choose block READ HOLDING REGISTERS (3) (after initiallizing card and socket) and question is what to write in SLAVE:START OF VECTOR? Following description above would it be 1009(hex) ->4105(dec)? and Vector length =1? Thank you for your answers!
  14. Hello again, Yesterday went to the object to play with above mentioned PID. Used PID server and now I understand why Emil likes it.. Great tool! By the way PID server's autotune gave better results than PLC's. After AT it gave P=1000 (100%) I=130s, D=34s. Then after some experiments (the PID was veeery slow) I came to P=90%, I=25s, D=37s. Results in pictures. What do you think? PID not tuned
  15. Good day, Once again I'm with question about PID.. Yesterday was testing object, where I have 3 PID loops: 1loop for temperature control and 2 loops for pressure. For pressure loops done autotuning, then changed some parameters by hand and it goes just fine and stable. But I got problem with temperature control loop: there's steam boilers with valves that heating water. I'm controlling valves to hold water temperature (SP). Theres big innertion on system, when valve opens, water temperature starts to rise, when reaches SP, valve starts to close, but water temperature still rises and overshoots about 10-12C (you know what I'm talking about). When I run autotune, it gives me such parameters: P=-0,1%, I=-1s, D=2s. With these parameters PID calculates CV 38% (valve position) and CV doesn't change anymore.. No matter that I tried to autotune several times with different setpoints it gives me same results. When I tryed to tune PID by hand at one setpoint (70C) it began to control temperature almost stable (+-0.5C) and valve gets at position (stable) and if necessary opens and closes by some %. but when i changed SP by 5C (65C) it reacted fast enough and stabilized again, but with error (about 1,5C) (66.5). Then I schanged SP by 5C again (60C) and again it reacted fast enough but error rised and was about 3C (63C). Then I tryed to change PID parameter to eliminate this statical error, but it gone wrong. PID gives me "integral wind up" or "integral wind down" messages and I couldn't get to previous state anymore. Now PID regulates valve in such way: when temperature is droping and reaches SP (t=sp) it begins to open valve, temperature still falls, valve opens. When temperature stop dropping and begins to rise it begins to close valve. And when temperature reaches setpoint, CV becomes about 0% (but valve is not fast enough) and temperature overshoots about 1.5C. And it repeats over and aver again. I couldnt make valve to stabilize and not to oscilate about SP. Spent half night trying, but nothing helped. Tryed different tuning methods, but no good. PID reacts different ways. When seems to stabilize about one SP, then I change SP and once again: oscilations and not stable system. Maybe someone had such issue? I need slow PID: it apons valve by couple %, waits, then opens more if theres need or closes by couple and so on. Is there anyway to do so? PV 0..100.0C (SP 60..90C) CV 0..100% Thank you!
  16. Good evening, Our customer wants PLC to count impulses of four machines, and to have results (count per minute) in PC (Excel). So I think cheapest solution would be Jazz connected via serial cable to PC DDE server. I want to ask what max length of serial connection cable can be used? Thank you!
  17. Thank you, Emil, tomorrow I'll try to connect TC directly and see what the results will be. Thank you!
  18. Hi, Thanks for answer! All thermocouples show an error.. Your idea about wire extensions is interesting - compensating cable connected to cabinet's terminals. From terminals to PLC IO-ATC8 module signals wired with simple copper wires (~1-2m long). Maybe it's good idea to connect directly to IO module. I'll try.. And I didn't understood about linearization of TC input.. Can you explain it to me?
  19. Good evening, Last week we had test drive for our temperature and pressure control. PID works fine, but there's a little problem with thermocouple inputs (we use ATC8 module). As I mentioned earlier, there were temperature error with sensor of outdoor temperature, but when we filled heating system and started testing I saw that all the sensors have the error of 4-5C (they all show 4-5C higher temperature) . There are connected 3x water temperature sensors ant 1x outdoor temperature sensor. We use K type thermocouple sensors (produced by our local manufacturer, as I gave Unitronics TC input specifications) connected with K type compensating cable. What should I do? I can subtract those 5C from every sensor mathematycally, but but I don't know if there will be the same error when temperature will rise 10, 20 or more degrees.. Please help..
  20. This happens only wit signals from steam valves, other signals are ok..
  21. Hi, I had the same problem before: Visilogic was working perfectly, done a lot of programs, but once, when I quit Visilogic and tried to open it again (as I understood) before it had canceled, the same textbox started to show every time I tried to start Visilogic. I tried to reinstall, nothing helped, except one thing: to install it o another directory e.g. on another disc. Hope it helps! Bye! Vidmas
  22. Hi, Once again, I have a couple of questions: 1. We have object where I use v570+ATC8. To ATC8 connected 4xTC and 4xAI(4-20mA). I sent specifications to our TC manufacturer and they made 3 TC (K type) sensors of water temperature and 1 TC (K- type) sensor of outdoor temperature. Water sensors are connected with K-type compensating cable (~10m each) and outdoor sensor also with K-type compensating cable ~40m long. When powered, water temperature indication is alright, but outdoor temperature (when in real was 8C) at once showed about 20C, then began to drop and after about couple hours it was indicating ~12C. Why is this error? Because of cable length or it has something to do with sensor? We changed sensor, but it's the same... 2. With the same ATC8, there are connected 4 AI (4-20mA): 2 inputs are speeds of 2xFC, and 2 inputs are the position of valves. FC's are 7.5kw and 2.2kw. They are mounted in cabinet, that stand next to PLC's cabinet (signal cable lenght ~3-4m.). In OFF mode, FC's are powered up, but pumps are not connected (with MC's) to FC output, in RUN mode pump (pumps never work together, but working pump is chosen by season) are connected to FC output. So there's an issue: In fast mode (819 to 4095) of valves position AI, when pump (7.5kW) is not connected to FC , AI's min value shows ~820 units, when pimp connected it drops down to 738 units (when valve closed) when valve is open it shows ~4096 units in both ways. Other valves AI's min value also drops down, but not that much. Is there's any thoughts about this? Checked the groundin, everything seems fine.. Thank you Vidmas
  23. Thanks, Emil, I understood it, when read Pid server's help file:) I have one more question: when assigning operands to Pid server, 32MI's autotune vector has to be the same as in the PLC's PID FB? And what for are operands CVp, CVi, CVd, RSTintgrl? Thank you!
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