The answer to my Rslogix5000, RSVIEW32 questions

[automation.engineer 0]

So I finally finished by end of career project using RSVIEW32 and an Allen Bradley ControlLogix controller, this site has provided allot of helpful information by people answering questions that I asked and by searching previous posts that had very useful information so now I will answer all the questions I had and to which I stumbled in to some problems and I was able to find the problem to them. Question 1: (they are not in the order I made them) Hello: I am having the following problem: I am trying to connect to a controllogix plc by using a serial data cable, the transmission rate is 19200 baud rate by using the autoconfigure utility. The program is rather big (about 1.2 megabytes) and while the plc is in REM it is rather imposible to move around it (it takes forever to do an action), If I look at the processor slow of the plc I got green lights .. What could be the cause of my problem and how can I access it? for a program like this I would need a bigger bandwidth like ethernet? We have been developing this for a University project (end of career project) and we just got the plc and things are starting to get frustratingThanks in advance!! Answer: For this I made a mistake when I configured the drivers on RSLINX I reconfigured it and put on the correct drivers, I also had a problem configuring the RSVIEW32 node using the correct drivers for a DF1 connection for a controlLogix, since all the drivers that appeared for a direct connection were for previous versions of the PLC I had to do a DDE topic in rslinx that pointed to the correct node of the physical controller, by pointing to this topic on the node configuration of RSVIEW32 I was able to connect to with a decent latency between the pc that had rsview32 and the controller. Question 2: How to print from an HMI? Since we ended up using a SCADA instead of a touch panelview it was easy to print since all that had to be done were to use PrintScreen commands used on RSVIEW32 and you can easly set it to use the default printer of the computer to print. Question 3: Before I can graduate I have to do a final project . The project that I choose involves upgrading the control system of an old sterilization machine using an ab contrologix 5000 . I already received some of the documentation from the machine but the most important documents have alot of important stuff missing, an example of this is that there is no document that outlines what all the variables that modify the documented phases mean, asside from the ones I can find in the process and instrumentation diagram (RTD,s selenoids etc). Since I have no experience controlling temperature and all my knowledge lies on undergraduate control theory, I am hoping for advice on anything I should worry about, any books or specific topics I should read up some more, etc. I also have some questions like : What would be the best way to implement and tune the PID gains (kp, ki, kd) if I don't have the transfer function for the system ( building up the transfer function of the system is out of the question since that would be a end of career project itself) ? should I use the old PID command or the PIDE? Answer: I ended up using the old PID instruction, the Proportional gain was calibrated first, then the Integrative, and the derivative to achieve the desirable stability and speed of the controller. Also it was an important point to put the PID instructions on a separate task of the periodic type that matched the 20ms analog module. Edited 18 Jun 2008 by automation.engineer

[Ken Moore 23]

Thanks for the feedback.

[automation.engineer 0]

Now here are other things I found important and that I would like to share with the forum: RSVIEW32 Problems with Displays with too many scripted fields: Rsview32 seems to have a problem regarding a screen heavily Scripted ( I made some displays that were supposed to display more than 40 fields of information with allot of IF. Else fields. This made lost of communications to this fields both emulated and connected to the controller. Also Heavily Scripted events may give some problems as well. So if you run in to this problem you might want to check your events and or displays with heavy logic , in my case I just removed some Aesthetic dynamic content and that fixed it. RSVIEW32 and Rslogix Tags: This probably is something basic but that made me stumble in to some problems when I started using rsview32. RSVIEW32 can only reference Controller Tags not Program Tags. Rslinx classic vs Rslinx Enterprise If you have a license for Rslinx Enterprise use it, it seems to be more efficient. Well this is for my answer and tips for those using for Rsview32 and rslogix5000, when some more things come to mind where I got in to trouble and I had to solve them I will post them later! Finally Thanks allot for all the people who took time to help out with my questions!

[paulengr 44]

Question 1: Also check processor scan times, and whether someone has altered the communication time slice to the point where you are getting poor responses. The PIDE instruction has a built-in autotuner. Frequently it's not hard to manually tune PID loops. Zigler-Nichols will also get you roughly in the ball park, after which point you can hand tune since ZN tends to be off by a significant fraction. It's also usually trivially easy to enough to measure system lag time and gain that you can implement this as a model-based controller (MBC), but then use the conversion rules to back-convert it into valid PID gains that work reasonably well. Also, the basic PID loop does not do feed-forward control so you have to manually add this outside the loop. Output = PID + feedforward calculation.

[automation.engineer 0]

Thats nice to know! I personaly wanted to try the PIDE FBD but since the companies standard was ladder logic i had instead to use the PID instruction. Thanks for the advice tho it can be helpful later!

[Ghettofreeryder 0]

RSView32 can program any tag, either controller scoped or program scoped. I will dig up an example, but you can browse to program tags in the opc browser of RSView32. I know this is possible with RSLinx and Kepware

[paulengr 44]

This is generally true. From an efficiency point of view also if you stuff all your HMI tags into a single UDT, then you will get just one packet transferred to the HMI instead of calls to individual tags. Edited 2 Jul 2008 by paulengr