mikey431

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Posts posted by mikey431

  3. Posted

    I want to know if there is any "cheap and dirty" solution for A-B PLC controller redundancy system ? I wanted to use controllogix L55 but it going to cost a lot of money to use ControlLogix redundancy system.As described in the A-B manual, i have to have to use ControlNet network with 2 same controller racks consisting of 2 controllers ,2 CNB modules, 2 SRM modules...Anybody has a better idea...

  4. Posted

    I am really dummy on Siemens so correct me if i am wrong. i want to create a momentary button on HMI, once it is pressed, it signal to start the logic.Is that possible to reset that same bit in the PLC if you use the set function in the HMI ?

  9. Posted

    I have WinXP prof edtion . Whenever I tried to save a project on a network drive, Rslogix 500 will crash immediately and same thing for Panelbuider32 software.I could use the SAVE AS but not SAVE. The strange thing is I can save other applications file (Word, Excel...) and I could even SAVE a rslogix 5000 project file but just not Rslogix 500 and Panelbuider32. ...

  11. Posted

    sorry for the confusion , i will try to fix everything and stick to this thread. However,there are one thing in the program that I am not quite sure about... I can see the SP and PV by 10 to get bettter resolution but i am not sure this is the reason why he have to multiply the Kc,Ti,LUT by 10 and multiply Td by 100 ? First i thought he did this because RG bit is set to 0 but ,as the manual on ML1200 , the RG should not affect the Td.. I attached the RSS file that i posted on other thread for reference. Heater_Loop.RSS

  16. Posted

    After playing around with the loop ,this is the trend i got.Here is the value i have for the loop: P: 2 I: 7.5 D: 0.05 LU:0.12 Blue is my control temperature Green is my setpoint Red is heater output what i tried to achive to shorten the time it takes to SP but also to avoid the dip that below 40

  17. Posted

    I guess my "goal" is both as the load change is affected by incoming temperature throughout the year and the setpoint will be adjusted. The reason for setpoint to be adjusted is we have a startup warmup mode for the system.This warmup mode will set the setpoint much higher than normal setpoint so the system can warm up faster.After system temperature reached the warmup setpoint, it will go back and control over regular setpoint. The problem I am having is after the setpoint is adjusted from warmup SP to normal SP, the loop will drive the temperature much lower than normal SP and it takes to long before it will dampen out and reached the normal SP.I dont know if there is a technical term for this situation but here is the scenario. let's say the warmup SP is 85 C and normal SP is 60 C. Once the SP is changed from 85 to 60 , the loop will drive temperature all the way to 50 and sluggishly gain it way to 60. I am trying to play around with this loop and don know if there is a standard way to tune a PID loop that you are not familiar with.I guess i can try to trend and see how fast this loop response. Any suggestion ?

  18. Posted

    I am working on an old program and trying to figure out why the previous programmer do certain things on heater PID loop block of an A-B Micrologix 1200.And I am pretty new on this stuff so stick with me. The first thing I dont understand is PID mode. I can see through the ladder that the Td is set at 1.15 on PID block but the mode is set at STI but i could not find any STI sub-routine and S:30 word value is 0.I do know if using the Timed mode, the timer need to be set so that the PID block is scanned at the rate that is set by the timer.However, I do not know the advantage of Timed over STI mode and why he does not have a sub-rountine to control Td. The second question is the loop output signal. The heater loop output ( 0- 100%) is scaled to match the 4-20 mA analog output signal which then is fed to an SCR and send power to heater. I dont know why he has to use this 0-100% output instead of feeding the loop control variable (CV) directly to the 4-20 ma output.I read couple tutor guides on the net and I believe that since the CV has higher resolution then the 0-100% output loop, feeding the CV to analog output will give better heater control. However, I am new to these stuff so I am not sure ...Hope someone can give me some insight on these topic....

  20. Posted

    I am trying to play around with PID ( for heater ) in Micrologix 1200. The objective is to make the heater loop to maintain temperature at the setpoint.However, once the setpoint is reached , we NEVER want it to go below the setpoint.Basically, we want to avoid the swing at the beginning before the loop get stablized.Not sure how to do this ? Thank you.

  22. Posted

    hi, my company has been using AB HMI (panelview 600 and 300 series). Now we have a new project that require the HMI must be able to operate nomal under -40 F and I am not sure there are any product out there support this much low temperature? I prefered some product that is easy to configure and can be program that is similiar to A-B HMI. Thank you guys.

  23. Posted

    I experienced a strange major fault in my SLC 5/05 processor. The reasons ,I think, are the MVI46-MCM Prosoft module I have in the rack. We have 2 of these module on rack 6,7 . While I was online with the processor (using Enthernet port), i got kick off to offline mode for no reason. I tried to go online again and put the processor in "Run Mode", I have a major error fault .Error codes are "659h" and"759h" and the message is "Specialty I/O module in slot 7 has not responded to a command as being completed within the required time limit." It is a major fault and I have to manually clear the error in the Processor status .Same thing happens after I download the program and tried to go online and put system in "RUn mode". My key switch is always in REM position. It does not happen if after I download the program , I dont go online and manually turn the key switch in Run position.Anybody that has experienced before ?

  24. Posted

    I use RsLogix 500 with a SLC 5/04 and PanelBuilder32 with Panel View 600. There a 2 comm port on the panelview : RS232 ( 9 pin) and DH+.What are my options that are available for me to communicate with PanelView as well as cables that I need ? It is the best if I can " see" both PLc and PanelView with RsLinx lite if it is possible.