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Showing results for tags 'PID'.
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Hello Everybody, has anybody created classical heating circuit in HVAC (control block)? Idea is to control mixing valve (0-10V or 2digital outputs) based on flow temperature and outside temperature. Please share it if anyone created block already. For any adittional help, I am here. Best regards,
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Hi, First time I am using PID on a Jazz. I want to keep the pressure within a system steady, regulated by a solenoid valve that has a constant pressure supply on it; and in turn feeds the closed system. Attached are my setup and I have a few questions: 1. My CV is the controlled digital output on the solenoid valve that opens when the pressure drops; reads of a 0-10V pressure sensor; and closes when that pressure reaches my setpoint. How can I setup the CV to a digital output? 2. My Process Value and Setpoint I have them linked to the same MI because I want to keep the pressure at whatever pressure the pressure sensor reads from the beginning. Is that correct to do? 3. I cant seem to make it to operate the solenoid valve because I don't understand what the Control Value MI should be in order to simulate a digital output. I also set its range 0 and 1 but it needs further processing Thanks
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We have about 50 Vison PLCs currently in operation in many projects. A few weeks ago we started to switch from Visilogic 9.8.64 to 9.8.90. We noticed that the PID functions were not working anymore. After a long time of troubleshooting we realized that we had to delete all "PID A.TUNE Config" blocks and rebuild them again. Is this a known problem? Is there another possibility to fix this? -
Hi, In a control loop I am using a proportional valve with an input -10V to +10V. With that input the process can be move left and right. When it has to be go to the right the input has to be positive, depend on the distance between 0 and +10V. When it has to be go to the left, the input has to be negative between 0 and -10VDC. Therefor I am using a output -10VDC to +10VDC. Now I will use a PID loop for it. Only what I find is a positive or negative PID control, so it can just 1 side on. You can switch this between cool and heat. But I wil not use that switch cool/heat, but just depend on the process value send the control value to negative or positive. Can somebody help me to explain how to handle with this. Thanks al for any help
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I'm a student studying at De Montfort University and currently trying to design a PID autotune programme to heat an element. The programme is designed using Visilogic and is for a V350-J-TRA22 controller. I have managed to display the temperature detected by a thermocouple on the HMI and the programme is almost exactly the same as the one shown in the 'PID' tutorials video on the Unitronics main site but when the controller is wired to an oscilloscope there is no output of any kind. Various combinations and checks have been carried out but nothing so far has worked. Does the autotune have to be carried out whilst the device is still connected to the PC and then the PID values entered manually or is this all done once the device has powered up automatically as it would suggest? I am new to Visilogic so if anyone could check over the programme (attached) to see if i have missed anything or direct me to someone who would, it would be much appreciated Joss test 25-30.vlp -
Hey there folkz. I have a test station here that i prep for 2021. Im not to well used for plc progamming so i hope i can get my answers here. The task is to make A program to be created in sequence with a percentage increase in air pressure in the tank, with fixed consumption. The working area of the tank is 0-5bar The sequence is as follows: Tank pressure increases to 25% The pressure is kept stable for 1 min Tank increases to 50% held for 1 min Tank increases to 75% held for 1 min Tank drops to 25% and the sequence is reatarted. i understand that pid is involved in one ladder by it self, so my question is how do i implement the values into a sequance cheers
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Dears, I am using PID functions...and I thik to have learned how this works but I don't found a way to "stop/reset" the autotune procedure when active!?...i try to explain what i need...I am talking about a management of heating element...if I start the autotune (PID config status = 2) and the real temperature is not increasing (heating element broken or not connected) what I have to do to stop the autotune to have back its status as "0"?...I tried to set "0" the BIT to enable the Autotune UDFB but the status stay at 2...I have wait many minutes with the BIT "1" without increasement of the temperarute...also with the BIT as "0" but nothing happened....now that I am writing I thought..."this is not a problem...will be enough "load" again the AT values!"...what is the right way? thanks.
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Hello! I'd like to make a PI(D) without auto-tune, so that I can determine P and I myself (D is going to be zero). Which FB do I use? -Mia
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Dears, is possible, during the PID autotune procedure, change the set point value? I mean...if I select "Cycles.Three" the procedure will increase to reach, and go over, 4 times the set point and also decrease 4 time to be below of the set point....is possible set (pass) for each of these 4 steps a different set point?...for example 70, 90, 110, 130? in this way the autotune procedure will be "masked" in what could be a standard start up of the system. thanks
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I need know how can reset in PID block in state -13 fault. Don't possible set value and value is retentive , same with download this application. now I am with PID locked in state -13. Peale tell me how out this problem. regards.
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Hi, In my program PID auto tune is not functioning. Overshoot came across when I tried it. After that I entered values manually in the PID loop.In that also little bit of overshoot could observed. May I get some help from to solve the PID issue.
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Good morning guys, I implanted PID auto tune program, is to present fail. Status : (-11) My question, the is resolution ? I’m Sorry for English. Thanks -
Bonjour, Actuellement, je suis en BTS et j'ai un projet de régulation de pression qui doit être fonctionnelle en fin d'année. Au niveau du bloc PID. A l'entrée, j'utilise un capteur de pression 4-20mA et une sortie 0-10V qui va être envoyée au variateur. Le problème, quand le destinataire est supérieur à la valeur de l'entrée PID, l'erreur est à 12 mais la sortie de la réaction, le reste à 0.
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Hi everyone! I'm having some doubts. I configured the PID Config FB and after that I did an AutoTune. I tried to run the PID control loop energizing the "PID A.Tune RUN" FB and it worked very good, but I have some questions. Once I finish my PID Control loop, do I need to reset numeric MI associated to Control Output value? If I don't do that, it remains with the last value before de-energize the "PID A.Tune RUN" FB so the Duty Cycle of PWM associated to that Control Output does not go to zero. Another question: when I de-energize the "PID A.Tune RUN" FB, the PID Status message is still 4, so it's like the PID is Running, but that's not true because it stop. Is that a kind of VisiLogic bug or am I doing something wrong? Thanks in advance, Gonzalo. PS: I'm using a V350 -
Hi , I have been working with the PID loop and it seems very complicated. I just want a simple PID loop (I'm anti auto tune) with manual mode (straight output) and automatic mode (with manual tuning) and I've seen posts that seem to imply that this can be done. Would I used the Run PID function? Or set the parameters in the config struct, Load PID AutoTune Data, then save it? and then Run PID? Would I use the PID AT Params or PID_Config struct or both? I only need a PI controller - so would I need to set SP, PV, P, I, Control Valve, Reverse Action (Does this account for a negative sign in the PI values?), and what else is mandatory at a minimum? Do I need Sample Time, and the Input and Output Highs and Lows? Is there a better way?
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Hi@all, U90 Help file says about #of PID loops: "Jazz controller loop capacity varies according to model." Unitronics website says about Jazz PLCs: "Auto-tune PID, up to 4 loops" I thought about using a Jazz JZ20-R10 for my Project and need two PID loops. When I select "PID" in U90Ladder only one PID is configurable. My question: Which Jazz PLC does have 2 or more PID loops? - or - Where can I obtain informaition about # of PID loops in Jazz PLCs I searched the website, the forum, specsheets and have not found any information about it. Thanks forward! Selli
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Hello, Using UniLogic V 1.21.51, I was hoping to create a 'Template PID' struct containing 'PID AT Params' and 'PID Config types', but these do not appear as options when attempting to add new members. The idea was then to also add some other housekeeping fields to my 'Template PID' struct, and use it as a type to create 24 global tags to manage 24 independantly-controlled oven zones in parallel. Is this possible? I was hoping to avoid having to uniquely name 24 sets of three global struct tags (such as 'PID AT Oven1 Zone1', 'PID Config Oven1 Zone1', 'PID Housekeeping Oven1 Zone1', etc.). Thanks, John.
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I am trying to retain the values of a PID structure but I do not know how to do it. Any ideas? Thank you.
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Hey there, I'm trying to set up a PID loop for a fan, and when I run autotune I don't get any control value and I get a status of -13. I have the set point and upper and lower limits set. I can't find any reference to a -13 status anywhere, can anyone help me out? Thanks in advance!
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Hello there! I'm trying to drive DC Motor with PLC V570 via PWM. This is for my diploma thesis so I want to do it nice and design PID controller in Simulink Matlab. In PLC I want to do identification of the transfer function for this system with step response. This is the first order system, so it shouldn't be a problem. Than I'm going to use this transfer function in Simulink to find PID parameters. At the end, I got P,I and D parameters from Simulink, and I don't know to transfer them into PLC. For example for closed loop system with discrete PI controller in ideal form P(1 + I*Ts*1/ (z-1)) (Serial PI) I have P = 1.93, I= 1.86[sec] Ts = 0.1[sec] Than in PLC I got Sample Time = Ts = 0.1[sec] = 10 Integral time = I= 1.86[sec] = 2, because it is defined in units of 1 second, Proportional band =(1/P)*100% =51.81% = 518 defined in units of 0.1% Am I doing this right? Could anyone please tell me what is the type of transfer function for PID controller is used in PLC Vision V570 (Serial or parallel)? And how do I correctly transfer parameters P, I, D into PID regulator in PLC. Thank you.
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Hello everyone, does anyone know how the PID autotune function works? Is it using a method like "Ziegler-Nichols"? I have tried to use the autotune function. It delivers values for Kp, Ti and Td. But when using this parameters for process, the way how it tunes is worser than worse ............. Is there any additional documentation for PID available? The integrated help of UniLogic is very rare.......
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Hello, I got the task to make a control system for a air conditioning unit which I guess needs 4 PID loops. One each for heating, cooling, humidification and dehumidification. Only two loops will be active at the same time. The product overview for Samba SM35-J-TA22 say "Auto-tune PID, 2 independent loops ". Does this mean that it is not possible to have 4 loops in the program? I would appreciate a quick reply! -
I am wondering about how the internal settings of the pid works. We have a process that needs to bee kept as close as possible to 85°C with a maximum og 90° and minimum of 80° this is a steam tupe heater which has an internal pipe with some fluid pumped through. The steam and the fluid enters at the same end and at the other end we have our temperature sensor that gives us the process value the steam is controlled by a valve controlled by 4-20 mA. The process fluctuates around 8° wich is considered to much. there are some other variables that affect this process which is best described as the temperature drops by a few degrees with some minutes a part. I am adding a new window where I can set the high and low value of the pid output range . So hopefully that will minimise the fluctuation a bit. But I keep thinking about the Input range. (process value low limit and high limit) I have these values set as 0 for the low limit and 1000 for the high limit = 0-100°C same as the range of the pt100. Should I rather set these values as the lowest value and highest value that we want. 800-900 (80° - 90°) I would really appreciate some help here. Best regards Bæring
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From the album: SOLARHARWEST
heatexchanger using a Samba 4.3 for dual pid control of oil and water pump's,and run signal for gps sun tracker, fresnel lens is not attached yet -
I am working on a large Kiln. We are trying to create recipes for the Kiln to process burn rates. We have many recipes but I can work with that. What we need to do is set the top temp (let say 1800 deg) and have it climb at a certain rate (lets say 300 deg per hour). I have been looking at the PID but I can only see what it can raise strait up to the degree set and stay there but be steady. I would more need to reset the PID after each hour for 6 hours to get it to smooth out but even that would be wrong because it would climb strait to 300 degrees and ride there until the hour was up. We really need it to take the hour to get to 300 degrees, then take an hour to get to 600 degrees and so on until it gets to 1800 deg. Once there we will want it to hold for a time and then descend at a certain rate as well. Does anyone have a Kiln program that we can refer to? I can write a real large program that will do this breaking it down to each minute (Like 5 degrees per minute only) but figure there is a better way. Any help would be appreciated.
