Flex727

Unitronics offers a training/certification class to be a Certified Unitronics System Integrator. It's a good class and I can recommend it.

I have to agree with sgull. I have never had a field failure with Unitronics products and consider them on par with products that cost substantially more. Electrical noise can affect any electronic component and can be compensated for.

I don't know if you really need the PLC to be the Master, by try it the other way first. Initialize the PLC Socket to Port 20256 and Slave. Set up the PC communications in VisiLogic to TCP/IP (Call). Confirm the PLC Name and IP address are correct, then try to initiate communications from your PC.

Be sure your PC and PLC are set up on the same subnet (e.g. 192.168.1.xxx). Check in INFO Mode what the IP address of the PLC is and the PLC Name and be sure those are properly entered in the communications section of VisiLogic. Make sure you are connecting the PLC and PC either through a hub or with a crossover cable.

There are quite a number of example projects that come with VisiLogic. Have you looked at those? They can be accessed through the top line menu: Help / Examples...

There is an Enable Data Entry tag you can use. Leave the Read Only box unchecked then use the Enable Data Entry tag to enable or disable data entry to the Numeric Box as needed.

Please send your contact information to me at blanier@arc-controls.com. I'm interested in taking a look at what your requirements are for this, as I believe I can help you and this looks like an interesting project. I am certified by Unitronics and have substantial experience in writing software to automate chemical delivery systems. I look forward to hearing from you. Best regards, Barry Lanier

How are you trying to connect to the PLC?

Any of us who consider ourselves real programmers are always looking for the most efficient, economical, and clever solution to a programming problem. But in reality, it's probably more important to write the code in such a way that it is clear and understandable to another person trying to read it. I like using a State Machine, when applicable, because it's very clear what is happening and it's very clear where in the algorithm you are when online with the PLC. Another side benefit is that it forces you to do what Joe Tauser suggests - organize and document your logic. I do other things, such as group similar or related short pieces of code using SB1, as follows: SB1 --| |-- <one line of code> | <another, related line of code> | <yet another, related line of code> This minimizes the number of ladder rungs and helps readability. Another important thing to do that surprisingly many people don't is to name the Operands in such a way that it is VERY obvious what that operand does. A few extra keystrokes today can dramatically reduce the time spent trying to understand what you were doing two years ago when you wrote the code and now have forgotten. I learned early on NOT to use the "Links & Jumps" tab to link operands on pushbuttons to jump to different displays. You will inevitably forget to enter one in the provided field. What I do is have a Subroutine called "HMI PBs" where I enter every display jump condition (I use a single MB for each display I will be wanting to jump to) and then everytime I have a jump PB in any HMI display, it will already be in the code and there is nothing to remember to make it work. I have an HMI screen where I display the vlp filename and the Visilogic version number so that I know what file and version was used when the PLC program was last downloaded. It also includes important information like the PLC Name and the Ethernet address, when applicable, so that it is handy. I always use Input and Output buffering, this can be important when the hardware unexpectedly has to be changed (change I/O module, or the technician mis-wired something). It also makes it easy to troubleshoot using an extra bit that can be controlled while online, or on a special screen, without having to "Force" I/O. I turn OFF access to INFO mode (set SI50 to zero) to the customer, unless properly logged in (I use multiple login levels on every program I write). This helps prevent problems. When access to INFO mode is needed I use SB36 instead of changing SI50. I also provide a button for a soft reset (using SB300) so the customer doesn't have to power cycle in the event of a system change or problem that necessitates a restart. This is off the top of my head - I'll add more stuff as I think of it.

I don't think tonymony was complaining about the lack of C++, but was merely explaining that he is transitioning from C++ to Ladder Logic. Tonymony, the picture you posted is too small to tell if your logic will work, but the way I would do it is to simply Store Direct either the number 1. 2, or 3 into an MI depending on whether I1, I2, or I3 is on, respectively. You can then use List of Texts, or List of Images to display the information on the HMI screen. There will be more complexity if 2 or more of the inputs can be on simultaneously. I1 1 MI0 -| |---------Store Direct-- I2 2 MI0 -| |---------Store Direct-- I3 3 MI0 -| |---------Store Direct--

Yes you can do that. Socket 1 will default to Port 20256 for PLC-PC communications. If you initialize Socket 1 to a different port, then you will need to initialize one of the other sockets to port 20256. Be sure you also use the PLC Name function block to give the PLC a useful name for communications from your PC.

Are you starting at 7000 hex (28672 in decimal) for ML0?

Did you re-test the bad PLC immediately after you successfully connected with a new one?

Then you will need 24 volts. If a 24 volt battery is not available or practical, buy or build a DC voltage booster.

I'm sure someone from Unitronics will come along and answer this definitively, but the rule of thumb I use is most of the PLCs will run on any voltage between about 10 and 26 (the spec says 12/24), unless they have I/O. Any I/O needs 24 volts. The V130-33-B1 will happily run on 12V, but all the other V130 models need 24V since they have onboard I/O.

I cobbled together some ladder code that shows what I do to connect to 2 devices using a single socket. This is just thrown together and hasn't been tested so there might be a typo or goof here or there, but it shows the basic algorithm. Comm with 2 Slaves on 1 Socket.vlp

I checked my code and see that I mis-remembered the timing. I allow 300ms for the complete cycle of a single PLC connection, communication, & close. I check for socket connection and wait 100ms for data communications to complete then perform socket close. When the self-resetting 300ms timer triggers I start the next cycle. I also use a bit which is toggled so I keep track of which PLC is currently connected.

I do this all the time due to the 4 socket limitation of the Vision products. Simply use indirect addressing for the IP (use can use the same port number if you wish), as you are doing. You also must re-initialize the configuration block with the new IP and re-connect the socket. Perform your data communications and after a short period of time, close the socket and repeat with the other PLC IP address. I use about 300ms timing between data communications and allow an additional 100ms for the close socket to complete.

If losing the program currently in the PLC is not a big problem, then remove power to the PLC, remove the battery, wait at least two hours, then replace the battery and power up again. If the screen remains blank, try the suggestions above again. If you can communicate with the PLC from your computer, then check the value of SI 9.

Joe Tauser is the expert on this, but waaay back when I was programming computers with old fashioned languages that used line numbers, I would always number by tens for the precise reason you state - I would always later find the need to insert additional steps and re-numbering can be a pain. With PLCs, if the algorithm is relatively simple and properly planned out, there isn't as much need to insert steps, so I usually number by ones and use the increment function. If it were a very complex situation I would definitely number by tens and use the store direct or addition function to increase the step number by 10. What I usually do is create a coil for each step number, such as: when MIx = 10, then coil MBx is ON, then precede each step with that coil as an activator (or gate). This allows multiple ladder rungs for each step in the state machine and a clear understanding of what is happening in the program. At the end of the series of steps, a condition must be satisfied to index the state machine.

My iPhone turned the picture upside-down, but I think you can still see what's going on.

I'm sure everyone has a portable 24v power supply they use to power up Unitronics PLCs when out in the field. But how many times do you find yourself without a handy 110v power outlet? Wouldn't it be nice if you could power your PLC off the USB socket on your laptop, or even a USB battery? Here is what I put together: This steps up the 5v from USB to 24v for the PLC: DROK® LTC1871 3.5V-30V DC Boost Converter Power Transformer Voltage Regulator 5V/12V Step Up Volt Module Power Supply Board http://www.amazon.com/gp/product/B00DWX8PM2 This cable has a USB plug on one end and a barrel plug on the other: StarTech.com 2m USB to Type M Barrel Cable - USB to 5.5mm 5V DC Cable - USB to Barrel Jack 5V DC Plug http://www.amazon.com/gp/product/B009C3CJG4 These are to provide barrel plugs and jacks for connecting everything together with a bit of simple wiring: E-outstanding 5 Pair DC Power Jack (5 x Male and 5 x Female) 5.5mm x 2.1mm CCTV Power Jack Adapter http://www.amazon.com/gp/product/B011YKCK5M This box fits the boost converter nicely so everything is neat and tidy: Hammond 1591MBK Black Flame Retardant ABS Plastic Project Box http://www.amazon.com/gp/product/B003A67F90 A cheap 10,000 mAh rechargeable USB battery will run a V570 for about 4 hours. This is usually plenty of time for field work, but larger USB batteries are readily available and are not much more expensive. I'm using this one: Anker PowerCore+ 10050 http://www.amazon.com/gp/product/B013HSQXZC

Thank you, Alexander!

Is there any way to determine if the program in a NON-enhanced Vision PLC (V120) matches the VisiLogic file without forcing it to match by downloading? In an enhanced Vision product VisiLogic will abort the download if they match, but this doesn't happen with a V120.

I should have some time shortly to help you with this. I recommend, however, sending your question to support@unitronics.com. They are very helpful and may be able to get you on the road without costing you anything.