Flex727

You can use the "Store Timer/Counter Preset" function to vary the running time in any way you wish. Create the logic you need to make the timer run how you want with an ML operand. Be sure the ML is in units of 10ms (e.g. an ML value of 500 would be 5 seconds). The Store Timer/Counter Preset will allow you to assign the timer preset to the value of the ML. You'll need to have some understanding of how quickly your analog input is varying and how stable it is to properly filter that input. You might be able to simplify your logic a bit by using TE (Extended Pulse) timers. Look up Timers in the Help file for a complete explanation of how all 3 available timer functions work.

Whoops, I didn't think through your logic carefully enough. You need to replace the inverted contact on ladder rung 2 (O2) with MB2 and replace the inverted contact on ladder rung 3 (O1) with MB1. Also, not sure what happens when the press is fully retracted or fully extended - is it okay for those outputs to just remain on?

1) What error messages are you seeing? 2) Yes, that will work fine, but I would use the Positive Transition contact instead of the direct contact for the pushbutton MBs. 3) Just set up the Hardware Configuration to match your PLC and you're good to go.

http://unitronicsplc.com/Download/SoftwareUtilities/Unitronics%20SD%20Card%20Suite%202.0.59.zip

217MB does not seem possible. I would be very surprised if a Vision PLC has enough memory to hold a project of that size, even after compiling. I would suggest running the Project Optimizer and also taking a look at the Projected Memory Map. A 217MB file size indicates something seriously wrong with your VLP file.

When MB20 turns off, you stop calling "StandardRoutine". When you stop calling Standard Routine, you stop calling "Gen1" routine. When you stop calling Gen1 routine, the PLC cannot turn off MB17, thus it stays on. Even if MB20 stays on, when the time expires in StandardRoutine, ladder rung 1, then Gen1 subroutine is no longer being called and MB17 cannot be turned off. Conditional subroutine calls can be very problematic. Design your logic to minimize (or eliminate) the need for conditional subroutine calls.

Thank you, Joe!

SB 372? This is new information to me. Ah, found it in the latest version of VisiLogic (9.8.22), but there is no entry in the Help file. Can someone from Unitronics provide a detailed description of the function of this System Bit and address Bisku's point about timer values?

Link to said USB oscilloscope?

Looks like a simple typo - paging Cara Bereck Levy! (We need a way to tag other users on this board).

I always figure if Joe says "That should have worked", then it's time to start looking at hardware.

Make sure your photoeye output is stable. If it blinks for even one PLC cycle it will reset your timer.

Ah, that's why I missed that in the Help file. Thanks, Cara, for the great response!

I just had a customer problem caused by this bug so I want to give this thread a bump. It was an older program that was written before I realized I had to take action in the software to prevent the problem. If this bug can't be fixed easily in the firmware (or VisiLogic software), I strongly recommend that it at least be mentioned in the Help files.

I don't think it's a bug so much as "forcing" requires 3 choices (Force On, Force Off, & Cancel Force), not just 2 (Set & Reset). It's "greyed out" because you need to right-click instead of left-click. I agree that a more intuitive interface is absolutely called for here.

Making mistakes is the fastest way to learn!

Just right-click on the left side of the ladder rung and select "Disable". When you're troubleshooting you need to isolate the problem as best as you can. Do NOT assume that there is something wrong with SB13. It will reliably pulse once per second. It cannot fail to do exactly that. Add a new ladder rung to the Main Routine to increment an unused MI with SB13 and you will prove that to yourself (I see MI2047 is labeled "test" - maybe you already did that?). Make sure you don't have any vectors that are overwriting your values also.

I think for this situation, you want to use the Binary Text element for each of your 3 buttons. Be sure to check the TOGGLE check box.

However, you do not need any I/O modules or other hardware. Just obtain the appropriate PLC, power with 12-24 volts, and connect with your PC or laptop. You can fully test with that setup.

SB 13 should only be on for one PLC cycle. However, I notice that you sometimes use a positive transition contact and sometimes use a direct contact for SB 13. I don't think it matters which one you use, but you are limited in the number of positive or negative transitions you can use in your project. I also notice that you sometimes use the increment function and sometimes use the add function to increment. Why the inconsistencies? I also notice that rung 2 of subroutine Trendy-24h is not connected to the left rail. None of this is the cause of your problem, but I don't have a V280 handy to load your software and troubleshoot. You have 8 instances of SB 13 incrementing integer operands - are all 8 acting abnormally, or just one?

+1 on this. Also, on this topic, it would be very nice if there was an easy way to clear out a whole section of operand descriptions (without using the group function when creating a contact or coil, which can be cumbersome). Even exporting the descriptions to Excel, deleting the unwanted descriptions and importing them back in does not work. I realize that there is a function for deleting all unused operands, but typically I don't want to delete ALL of them, just a particular section.

From Wikipedia: The SECS/GEM is the semiconductor's equipment interface protocol for equipment-to-host data communications. In an automated fab, the interface can start and stop equipment processing, collect measurement data, change variables and select recipes for products. The SECS (SEMI Equipment Communications Standard)/GEM (Generic Equipment Model) standards do all this in a defined way.

Anyone ever tried to communicate with a Unitronics PLC using a SECS/GEM interface? Any suggestions on the best way to go about doing that? I'm really only needing the lowest level of communication where a host queries the PLC to get a few bits of data. The PLC would remain in listen mode only.

Make sure the subroutine that does the multiplication is being called. Also make sure MI 22 isn't being overwritten later. I presume both MI 16 & MI 12 are both reasonably small to avoid overflowing MI 22.

Unitronics has a number of example projects in the Help menu of VisiLogic. There are also a number of training videos available online. Check those out and see if it helps. You can also search the internet on Ladder Logic to get a basic understanding of how all this works.