Flex727

While looking at the file properties, I see that they are different between the icons with the lock and the icons without. Clearly this is a Windows thing - I don't know what it means, but it seems to me that it's not Unitronics related.

Are you saying this only happens with Unitronics files? My experience is that NAS drives often use some file system that is not entirely consistent with Windows. Not sure why, but perhaps so that they will be compatible with other operating systems also.

@Cara Bereck Levy, we were discussing this a few weeks ago - any idea what's wrong?

THIS is why I participate in this forum - I learn something new every day. Thank you, @Cara Bereck Levy! I wish I had realized this years ago. Okay, Cara, tell me this: when I look at .vlp files in Windows Explorer there is sometimes a lock on top of the VisiLogic icon in front of the file name. What does that mean?

Very small 24v wall warts are readily available, but for a PLC alone, any 12-24v power supply will work if it will supply about 500 mA (24v) or 1000mA (12v).

And while we're at it, we need the ability to lock the elements in place after they're lined up. I am constantly struggling not to move elements by one pixel when double-clicking to modify some property. Just a single property that applies to the entire HMI screen to lock all elements in place would be sufficient.

The PLCs are relatively inexpensive. If you need to do complex work, you're much better off simply buying one. You don't have to buy any of the I/O. Unitronics purposely designed the PLCs to not care about I/O so that development work could be done on the PLC alone.

U90 Ladder can be very non-intuitive, but you need to link a MB to a Variable and select "Bit (on/off)". Then in the HMI Display, you assign that variable to a display element.

You need to call Subroutine 1 in your Main Routine or it will not run the ADD function. I don't see anything wrong with Display 2 except you've changed the background color to black.

You should post your code, but a few things to look for are: -Make sure the ADD function is being called - is it in a subroutine? -Make sure A, B, or C are not being assigned elsewhere in the program. -Double check that all the operand assignments for A, B, and C are correct, both on the HMI and in the ladder.

Contact support@unitronics.com for help with this issue.

What is the answer to this math problem: 7-1x0+3/3=? If you understand the PEMDAS rule you will get the correct answer of 8. However, if you just run the operations from left to right, you'll get 1. Every ladder rung in your program must be compiled to machine language before the PLC can execute the code. Do you know all the rules the compiler will use when you have a very large net? I certainly don't. Remember, like all computers, the PLC can only do one thing at a time and a large net can provide ambiguity (to humans) so the result can sometimes be unpredictable. To avoid this potential problem, always make your nets reasonably simple and break them into functional parts. It's also easier to troubleshoot and for another programmer to understand what you're doing.

This question is unclear. Can you restate it? I will say that something strange happens if a positive transition contact initiates an HMI call and then later in the same cycle if there is another use of the -P- it is ignored! As follows: 1) MB 0 goes high, MB 1 = zero 2) -P- of MB 0 SETS MB 1 3) -P- of MB 0 calls HMI screen (from ladder) In this scenario, MB 1 will be SET and HMI screen gets called. But reverse rungs 2 & 3, and the HMI screen gets called, but MB 1 remains zero. Why is that?

Have you tried MODBUS TCP? That's fairly universal.

I still get "Page not found". I think @Ausman was referring to the fact that the old forum is simply not at the linked address, not that he couldn't find a topic while searching.

You can use the IO-D16A3-RO16 for Relay outputs or the IO-D16A3-TO16 for transistor outputs with the expansion adapter EX-A2X.

Yes, you absolutely can attach expansion I/O to the V700. What I/O do you need?

Same here - "Page not found".

Great source. Thank you, AlexUT!

+1 on this!

I think it's a futile request. Sometimes vibration sensors can be affected by noise, or higher frequency vibration that isn't useful to measure. For instance, with a large pump or motor, you're probably looking at seeing a problem with a rotational bearing, or something similar, which will result in a low frequency vibration. Any high frequency vibration might mask the signal you're looking for or cause false positives. I know it can be a common practice to place an electrical low-pass filter between the sensor and the ultimate measuring device, but I was thinking maybe there was a software way to accomplish this. I suspect there is really very little (or no) frequency information available to the PLC on the 4-20mA analog input, but thought I would check it out anyway.

Has anyone ever tried to implement a rudimentary low-pass filter in ladder logic? Is it even practical?

Yep, works for me now, too. But, @Joe Tauser, why do you commit the cardinal sin of having two networks in a single ladder rung?

I get an error also. I'd love to play with it a bit if I could get it to load.

I'm curious as to what your motivation was for the transfer to UniStream.