Flex727

Thanks for reporting back your findings!

My understanding may be a bit incomplete, but here is my experience on this subject: When you opened the 9.8.9 project in VisiLogic 9.8.31. you should have gotten a warning message that the project was last saved using 9.8.9 and database 150. VisiLogic 9.8.31 uses database 152. This will mean that the PLC firmware will need to be updated if you want to download the project into the PLC using 9.8.31. VisiLogic will warn you about this and will not allow you to proceed until the PLC is updated. If you do all this the likelihood of having a problem is very low, but I rarely do. Every programmer has his or her own philosophy on this. Mine is that if the PLC is working well at an installation, I do not update the firmware unless there is some specific need for it. I keep all the older versions of VisiLogic on my computer and use Version Swapper to select the version used on that particular PLC, make the program updates, and download. Other programmers like to update everything to the latest software and firmware versions whenever possible. Also, if there are multiple Unitronics PLCs in service at a particular location, I try to keep the firmware version the same on all of them for consistency - another reason, in my mind, not to update. So, to sum up, I would download 9.8.9 and use it in your situation. Other programmers might do it differently. I don't think there is a definitive right or wrong here. Obviously, if you can't get Version Swapper working it leaves you little choice. However, I will say that I've never had a single issue with Version swapper. Two things to remember about Version Swapper: 1) Always use the version of Version Swapper that was installed with the latest version of VisiLogic, and 2) As with all Unitronics software, be sure to install and run "As Administrator".

This is fascinating. I'm learning some things about the differences between expansion I/O modules and Snap-In I/O modules that I haven't thought much about in the past. My thinking is that there is a more "intimate" connection between Snap_in modules and the PLC than expansion modules. There are 8 pins (lines of communication) between expansion modules and the PLC, while there are 34 pins connecting the Snap-In module to the PLC (they may not all be used and at least 2 or 3 are used for power & ground). This would seem to allow for certain additional capabilities that Unitronics takes advantage of. Clearly one of them is the ability to interact with the HSC in real time that can't be done with the expansion module. Any of this sound right?

Ausman is correct (as usual). Only the Master can Read & Write. The Slave merely listens for requests from the Master and allows the registers to be Preset (written) or Read. The Slave cannot initiate action (at least directly).

@Cara Bereck Levy, this issue might need to be addressed in more detail in the help file. If there is a difference between Snap-In and expansion modules in how the HSC behaves, the customer needs to know for proper hardware selection.

You need to provide a LOT more information before someone can attempt to help you. What PLC? Which I/O module(s)? Is the Run command given via a Digital Output from the PLC I/O or some other communication? Has this been a problem all along or is it new? If this has been happening all along, it sounds like a logic error by the original programmer. If so, it may be a simple fix. Do you have the PLC program .vlp file? If so, attach it and someone should be able to give it a look over.

I've never had that happen, but if you've fully removed and re-installed VisiLogic and the problem persists, it sounds like a problem with your PC.

Thank you for that!

Also, I thought the Immediate Reset HSC should work, but I can't find any Help entry on that. This is not a function I've used recently. If you don't get any other help here, just send your question to Unitronics Support. They'll get back to you pretty quickly.

Sorry, replied without thinking. You need to configure a hardware reset. One specific digital input can act as a reset - see the help file. Another thought is to use an ML or DW to avoid overflow.

Does Reset Numeric or Store Direct 0 into the MI not work?

Post your program.

What do you mean by "crashes" and how do you know it's being caused by the scan protocol function?

What is it you're trying to do? As I said, each MI holds two characters, not just one.

Which PLC are you using? Is there ASCII data in those MIs? Also, be aware that each MI holds two characters. Perhaps the string display is seeing a NULL character and stopping?

Flex's Law of Ladder Logic: Unitronics does NOT charge you by the rung! Break up you code to the most simple logical elements. It makes sure you get the compile you want AND makes the code easier to read and debug.

Burn stops the PLC. A regular download that doesn't affect the HW configuration or Data Tables does not stop the PLC.

A download will not place the PLC into stop mode unless there is a hardware or data table change (there may be a couple of other conditions that I forget at the moment). However, there is a download option called Stop-Download-Reset which will force the PLC into stop mode during download. Try that and see if it resolves your issue.

By the way, you can manually check for the need for defragmentation and take care of it, if needed, before you save. You can find the item under the Build menu. I rarely bother though.

After repeated editing and saving of a VisiLogic project, it can get fragmented and needs to be rearranged. This is not unlike what can happen to a hard drive. It is perfectly normal and won't cause any problems except for the occasional delay when opening a fragmented project.

That's because (as I see it) VisiLogic is not really online with the PLC. All it is doing is looking at every operand and displaying its value onscreen in the VisiLogic program. Red lines are drawn through contacts and connectors (when the bit value would pass power) and red lines are drawn for the ladder rails. This is why you can go online with a completely different program than what's in the PLC and you won't know the difference on your PC screen (except for the logic inconsistencies). It's not a problem if you understand what's going on.

Yes, just substitute an MB for the I 0 in the example above. Then link the MB to a button on the HMI. You can use either a regular pushbutton for momentary contact, or use a Binary Switch with the Toggle function checked.

Yes, add a line after your linearization blocks, as follows, should do it:

You can only have one version of VisiLogic properly installed at a time. Version Swapper will allow you to install multiple versions and run them. While you can have the files available for multiple versions of VisiLogic, you need Version Swapper to switch between them. I think there's a sticky post in this forum to explain it. Post again if you can't figure it out.

Do you use Version Swapper?