Davka

I have stayed on 1.023Z and have not encountered anymore problems with the editing so far. Haven't really had to do much work with PLC lately so didn't bother to upgrade yet. The program is terribly slow sometimes though like Luke.S said. For me it's mainly when writing to and reading from the PLC. Could be the fact that I'm connecting through my GOT though. Does anyone know/remember how to get a list of all the devices that are currently in use in a project? I use both GXW3 and GTD3 so it would be nice to do a cross reference so I don't accidentally start sending stuff into the wrong places from the GOT.

Hello, I would like to use the logging function in the GS2110 to collect some information. We have a pump where the flow is monitored via flowmeter. I would like to log a step response where I set the pump speed to some value and log the corresponding flow. Mitsubishis manual does give some information but it's not very clear. Has anyone done this and maybe have an example to share? Best regards, David

Hello! I am fairly new to the PLC world and I have worked mostly with Mitsubishi products. Right now I am doing some work with an FX5U and a GS2110 touchscreen. The code is a mix of LD for the meat and potatoes stuff and ST for more math-intensive parts. My question is how you guys generally organize your code with respect to inputs from HMI, stuff happening in the PLC and outputs to machines? I have made state machines for the sequential processes such as weighing in materials and more direct "stuff goes in, stuff comes out" code for the manual modes. The flow from HMI out to machine is sort of like this: HMI Inputs -> PLC -> PLC decides whether this is an automated process or a manually controlled one -> Execute the corresponding code -> Activate proper outputs, use sensor feedback if it's an automated process I hope this makes sense. Would be nice to get a feel for general workflow and organization from other people who work with this. Best regards, David    

So do you need very exact temperature control or for the temperature to stay close to a value with some margin?

I don't know what kind of system you are controlling but if it is not too important that the temperature is very precise you can use bang-bang control as well. This is very simple but not as precise as PID control.  What you do is that if the temperature is below the desired value, put the heater on maximum. As soon as the temperature is equal to or larger than the desired value you turn the heater off. This may cause the temperature to fluctuate a bit around the desired value but if it is OK this is a very simple method to implement.

Like Bryll said, you need to set Kp, Ti, Td and Kd to begin with.  As it looks right now you have all of them at 0 which means there will be no control signal to the process. There are a host of different methods for setting up PID controllers. The most widely used controller is the PI controller meaning it has a proportional part and and an integral part. Using a derivative part is only necessary in some applications and it needs filtering of the input signal to work good. I would start with changing the proportional gain (Kp) until you see that the process value is equal to or close to the desired value. More gain will make it faster but might also result in overshoot meaning the temperature might go above what you want for a short time. It is better for it to be a bit slower and not overshoot. If the temperature remains stable but not quite at the desired value start increasing Ti until the process value settles at the correct value. Too much Ti could result in oscillation and then you will need the D-part to fix it. I hope this helps! Feel free to chime in if anyone thinks my tips are wrong or something is missing.

I found the solution to this. There is a trigger option in GT Designer for inputs/buttons and you can set the input/button to OFF if a certain register/device is 1.

Hello! I am currently working on a project where the user can input a recipe on a GS2110 touch-screen. If it is possible I would like to prohibit changing any parameters once the process has started. Is there any way to do this? I figure you should be able to monitor a bit and if it is high (process running) the user may not change any parameter on the screen.  The PLC is an FX5U and the particular process itself is ye olde weigh in a set of materials and then start mixing. I am using step ladder instructions since I mostly worked with SFC prior to this project. If there is no way of locking the touch input I reckon I can copy the parameters sent from the touchscreen while in state 0. As soon as the process starts, the PLC will stop copying and the rest of the process will work with the currently non-changeable parameters. Best regards, David

Just reporting that my problem has been resolved. It seemed like the issue was apparent in v1.017T of Gx Works3 which I was using. After updating to v1.022Y the problem dissapeared. I'll be on the lookout for weird editing buttons as well in case it reappears.

Where exactly is this Edit Line option located? Some dropdown menu or in settings?

I will check if I've done something like that. Only been getting into the programming stuff the past two weeks. Thanks for helping out!

Hello everybody, new to the forums and fairly raw PLC programmer. I've recently gotten involved in a project for a customer where it was decided that we would use a Mitsubishi PLC. This is because they've used them in earlier projects with good results. The PLC in question is an FX5U which I figured would be good since it allows for a mix of LD, ST and FBD. LD will be used for stuff like alarms and sequential programming with some inline ST for math-related operations. I'll also try some FBD since it reminds me of Simulink which I am much more familiar with. My question for you is about Gx Works3. When editing ladder diagrams you can (or should be able to) insert an empty row using Shift + Insert. I frequently get a pop-up saying "Edit position is incorrect." This is frustrating since I feel like adding a new row is one of the most basic operations you can do in the program. I also get this message when trying to add comments. It seems like its very random with where you can and can not add rows/comments. It leads to having to add a row somewhere and then restructure the whole program so you finally get the empty row where you wanted it in the first place. The same thing happens when say you would like to cut/copy a row and paste it somewhere else. Has anyone else experienced this problem or am I doing something wrong? I know I am in write mode but it still gives me problems. Best regards, David EDIT: Might be this should have been in the iQ Works Q&A thread. Apologies if that is the case.