Emil
-
Posts
455 -
Joined
-
Last visited
-
Days Won
10
Content Type
Profiles
Forums
Gallery
Events
Blogs
Downloads
Articles
Media Demo
Posts posted by Emil
-
-
Can sopmeone send a demo to simulate the problem to support@unitronics.com? Which VisiLogic and OS version you're working?
The operation must be immediate. We need to investigate and see whay in some specific cases it's not. Then we will find soluiton.
Waiting for simple (as simple as possible) demo to show the problem!
-
The answer strongly depends on the specific system.
Motor speed driving:
What is the interface? Analog input? If so:
You set the inpout of PID the frequency from encoder 9there is a special mocule in VisiLogic, which measures frequency very precise with resoluiotn of 0.01 Hz!)
The output to analog signal.
As result, PID will change CV, linked ot AOand this way will change - increase or decrease - the speed of thhe motor!
No "two way PID" needed at all!
Heating to temperature and then holding it is a classic PID application. In this case PID regulates the output energy (usually PWM) to the supply the energy needed to keep the system in stable state (compensate energy losts) and thhis way to keep the temperature stable.
Onece again - no "two way PID" needed - at all!
If you have specific system, please give more info about it and we will find the way to control it.
-
What is your system? Why you want to perform heating and cooling?
-
Hi Emil,
Log all the data in SD card - no any problem - standar operation. There are few ways to do so, including direct in CSV format (compatible with Ecxel and Open Office).
V570 supports 8 trends x 8 curves each. Without and "tricks" you can view online and save to SD card up to 64 values per controller.
With some tricks, probably you can veiw all the values in graphical way (still up to 8 per display), but you cannot log direct the trends to SD this way.
-
Hi Deke,
The times VisiLogic was developed, about 10 years ago, most of computers were running on DOS mode, monitors were 14", mostly B/W and took quite a lot place. "Multi-monitor usage" was not even dream...
-
It seems you just need to use Linearization block (math menu) with the rigth settings for X1, Y1, X2 and Y2.
If you just want to "invert" AI, for 4-20 mA 12 bit the values ned to be
X1 = 819;
Y1 = 4095;
X2 = 4095
Y2 = 819.
I guess you wil lneed to make conversion direct to length, but the tip above will help you to find the direction.
-
Please send me the application to support@unitronics.com.
-
The condition to activate FB PID config module must be active for scan 1 only.
The module must be located in a place (main routine, some subroutine) which is scanned all the time - despite the condition is not true.
-
Hello,
I think I know where the problem is - at least one of them.
Config block must:
1. Be activated with one scan condition (usually SB2 - power up bit)
2. Be located in a subroutine, which is scanned continuously. Usually we recommend to put it in Main routine.
As you describe the application, it seems your PID Config module is located in subroutine, which is activated and scanned only once - during power up. This answers the first condition, but not the second.
Please try as a first step to move FB PID Config to main routine and activate it with SB2. Let's see what will be the result.
About driving solenoid valve - I know many people who use solenoid valves this way and obtain precise proportional control via relatgivelly simple hardware. But - it's up to you... At least use my first suggestion - to drive the valve time proportional via FB PWM. The way you're working is practically ON-OFF and I'm not sure working this way I can help you too much...
-
Hi,
Are you sure:
You activate FB PID configuration with one scan condition (SB2)?
It's located in subroutine, which is always scanned (Main routine)?
Can you try the follow:
1. Update VisiLogic to V9.01 from our site.
2. Open yor project with the new VisiLogic version. Save it.
3. Delete FB PID.
4. Perform Build All;
5. Write again FB PID. Perform again Built All.
I'm quite not sure the way you drive the output is a good one! It seems more like ON-OFF. I'll recommend two other options:
1. Set CV range to 0-1000. Use then FB PWM to change the duty cycle and this way driving time proportional the valve.
2. Set existing HSO to relativelly high frequency - let's say 100 Hz. Then - connect the valve and change the duty cycle. In most of solenoid valves as result you will have the valve opened proprotionally to duty cycle, which in fact is CV!
-
Hi,
Can you send me your application?
Did you take logs with PID server? Can you post them too?
Which version of VisiLogic and OS you're working? Can you update to recent ones?
What is your hardware?
-
Hi Tim,
The idea of bit, stating confirmaiton of the operation, is, when this operation for some reason takes more than one scan. Giving the command to perform the relevant operation, the controller continue its normal scan. In many cases you want to know when the operation is perfomred to go to next relevant action.
Read/write to DT is performed immediatelly. The controller perfomrs it and then continue the scan. You can put operation, depending on the DT read/write on the next scan after relevant DT module and you can be sure this operation will be executed.
Why you think such "confirmation" bits are needed?
-
Hi Sonny,
What is the logic you need ot perfomr between temperature and pumps. Let's say - you have 7 inputs (temperature) and 3 outputs - pumps. Please explain in ordinary words what you need to perform as system. What is your final goal?
-
Hi,
Locatging vertically expansion modules is very often applied soluiton. currently no problems with it.
-
Out of doubts this is a good idea. It reised few times here. But the layer of expansion communication doesn't let such option. In fact - as compromise to this request RC1 was designed.
Anyway - we are taking this idea in mind and will use any option to implement it.
-
Hi Mare,
Can yo explain more detailed your idea. It seems interesting, bu I'm not sure I fully understand it...
-
Hi Blitz,
Thank you for the idea. You're right, indeed. But making this will need fully redesign of EX-RC1. Currently, thhis is not in our plance for 2011.
-
Hi Hightech,
You give the medicine without knowing the ilness. What you'r4e offering can work, of course, but:
1. Force integral error to 0 must work! I don't know any case someone else claimed it doesn't work.
2. I'll be glad to know more about Mika's system.Whyintegral error increases so critical?
3. Mika - can you take a log with PID server and observe CVi? You can add in your application PID module Read Control component and then add relevant MI for CVp, CVi and CVd in PID server. This will give you very clear picture of what is happening withhin your PID.
4. Which OS version you're using?
5. How you're performing Force Integral error?
-
Hi VS,
I'm pretty sure you know, but anyway - in Ethernet you can open 4 sockets and - as result - to communicate with 4 devices at a time. Are you already using all 4 sockets?
If the controllers are already connected in Ethernet LAN, there is a great chance that you don't need any changes in hardware/wiring. Probably only programming. Take a look on the funtions TCP Raw and UDP Raw. Those are Unitronics Ethernet Multimaster protocols and it seems at least you will not need to change all the conception of data flow in your project.
-
Dear Vadimas,
Sorry to say, but this system is built in the worst possible way!
1. CANbus network is "pure" dayzy chain. This means the cable needs to pass from one unit to another. You did it with "star" topology, wich is definitelly wrong!
2. CANbus is very sensitive to the cable. You MUST use the right cable - DeviceNet Thick one (see attachment).
I see two options:
1. To totaly redesign your network. In this case please follow strictly the instructrions in VisiLogic's help.
2. To switch to Ethernet. In this case you will need to add Ethernet card to the controllers, switch/hub somewhere and to rewrite the communication part of the application, but will not need to change the cables.
-
Can you explain what are the values for linearization and what exactly is the problem?
-
In general,
- after setting some legal PID parameters,
- when you change PV somehow (connect potentiometer to the input, moving temperature sensor from glass with cold water/ice to galss with boiling water... or just linking temporary to MI, which is not linked ot hardware and then changing the value in this MI), or
- when you change setpoint;
You need ot see CV changing.
Please note - this test is -"go-no go" test. You can see if your program is proper at all, but you cannot tune the loop.
Very useful tool for debug, observe, log and tune PID loops is PID server. You can find it in VisiLogi or U90Ladder - in Tools menu.
-
What exactly you want ot program? M90/91 itself or PC to communicate with it?
If it's the PLC:
U90Ladder is a programming environment by itself. you don't need to work with a part of it. The programming language is Ladder diagram.
If you want to communicate with PC:
In Unitronics web site www.unitronics.com > Support page > Downloads > PC to PLC communication tools you can find some DLL and .NET driver, winch I hope will be useful.
-
Can you attach your application, se we can see the problem?
Set bit by email
in Vision & Samba PLC + HMI Controllers & VisiLogic Software
Posted
The controller cannot receive mails - it can only send...