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Hello all, I am new here. I have some basic experience with industrial automation and programmable devices like PLCs and vehicle engine computers, as well as C#. Now, I ALSO have a big stack of huge problems regarding a neglected/abandoned Public Water System (EPA regulated) that a small rural community (approx 200 souls) depends on. After discovering that our water system had been abandoned and all its money embezzled by a now-dead crook, I took charge of the situation and got the system powered back up and semi-functional again. However, we have a high-priority issue brewing... the water treatment plant is operated via a Mitsubishi Alpha2 PLC (14 channel model, with Analog output module) and two Variable Freq. Drive units: An Eaton SVX9000 sized for a 30HP motor, and a Mitsubishi F800 sized for 7.5HP motors. From 2006 to Dec 2021, the active program loaded on the PLC has been the ONLY copy of the program in existence! When I discovered the PLC and realized there was no backup of the program and no Serial cable to retrieve a backup, I immediately researched the AL2 unit and found a Serial cable on eBay and also purchased a spare AL2 and Analog module. I have successfully obtained the AL-PCS/WIN 2.70 software and extracted a copy of the program. At this point, the emergency has been dealt with. However... The PLC program is incomplete and partially non-functional. It is not behaving as expected according to the limited Distribution System drawings I have available. I want to debug and fix the program, but now I have run into a SERIOUS problem trying to make sense of the extracted program. Because I don't have the original file that was used to render the final program and write it to the hardware, the "map" of where all the functions and objects should be graphically laid out within the editor has been lost. When I open the raw file in the Alpha2 editor software for the first time, the editor alerts me that a file is missing and it must reconstruct the visual representation of the layout from scratch. When it imports the raw file, the entire layout is crammed into a ~640 pixel wide column that takes 5 or 6 pages to scroll through! It is impossible to reverse engineer the PLC program when it looks like this! To make matters worse, there is no "group objects" function that I can find, and when I expand the width of the layout, I can only drag ONE item at a time to a new position... if I try to multi-select two or more objects and move them, the GUI editor freaks out and scatters the selected icons all over the layout. I have already tried once, spending about 20 hours, trying to re-organize everything, but it is extremely labor intensive and I have barely made any real progress! PLEASE tell me there is a way to repair this layout without spending another 40 hours dragging every icon around 100 times. It feels like an exercise in futility at this point, especially since the program is less than 5000 bytes -- but I have no other alternative...this software runs a critical piece of public infrastructure and I NEED to be able to maintain it. Any help will be greatly appreciated by me, and my little community who can't drink or shower without this rat's nest of a program: What a nightmare! This is as far as I got, and I am about to abort the attempt and start over from scratch, because now the program seems to have new malfunctions.
Sorry first up for what may seem like a simple post / question, however I am pulling my hair out with reading the programming manual and have had no help from Mitsubishi's PLC technical support team. I have a Mitsubishi Alpha 2 (AL2-10MR-A) that I am using to count the starts of a jacking pump via input one. The intention is to have output one operate when the jacking pump start count reaches 5 within a 24 hour period. When the 24 hour period has expired, the count will reset to zero. The count will also reset to zero when a manual keypad key is pressed. I have been able to figure out the counting and reset via the keypad no bother, however, including the 24 hour clock reset is proving difficult. Has anyone had any experience with adding the 24 clock function at all, and can offer advice or examples? This is being programmed directly via the keypad. TIA
Hi Although I have used programming languages like basic and C for many years, I have recently tried to get to grips with programming (with the software (not direct)) the Alpha2 I have to admit that I am struggling! I have made a little progress since I worked out that you have to build almost everything at a very low level. But I still can not work out how you make variables that can be used in the program? For example : If condition A is true X = 10; But if condition A is false then X = 2. I have tried using the bit inputs on the math FBs to enable/disable values of X, but although this will initially alter the value , sending a 0 bit merely freezes the calculation and the value does not change. It seems like it should be such a simple thing to do? Is there a fundamental concept I am missing? Any help would be greatly appreciated