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Flex727

MVP 2023
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Everything posted by Flex727

  1. Many years ago (many, many) when I was young and stupid (okay, slightly less stupid), I had some confusion about PLC Ethernet comms (didn't we all?). I had the need recently to have another look at a program I had written back then. This program, running on a V1210, exchanges data with several V570s simultaneously using MODBUS TCP. Each connection uses a separate socket, but all 4 sockets were initialized with the same port number, 20257. This program is still in the field and running flawlessly. My question is, why? How is it possible for the communication to work properly when all the sockets have the same port number? How does it all get sorted out properly so that the data ends up in the correct place?
  2. Your VisiLogic installation includes a number of example projects. In the VisiLogic main menu, go to Help/Examples.../Version 900/Project Examples/Communications/MODBUS There you'll find examples you can review and adapt to your situation.
  3. And by the way, this is a volunteer user forum, not official Unitronics Support. Unitronics does provide support elsewhere.
  4. It looks like you set up Socket 3 for comms, but you set up your MODBUS configuration for Socket 2.
  5. Also, don't get confused between your wired ethernet address and your wireless address on your PC. When you do IPConfig in a command window, confirm which address is which since they are usually on different subnets. You want to make sure you use your wired IP address subnet.
  6. That is your Subnet MASK, not your subnet. Your subnet is 192.168.0. You need to make the subnet match between the PC and PLC (the first 3 octets must be the same and the 4th octet different). The subnet of the PLC, as you show above is 10.2.5. Also, are you certain that 10.2.5.83 is the IP address of the PLC? Even so, go into UniApps and change it to 192.168.0.xxx (anything other than 71). Or, you can go into your PC network settings and change your PC IP address to 10.2.5.xxx (anything other than 83). Once you do that you should be able to communicate if you are plugged into the correct port with a crossover cable or through an ethernet hub.
  7. Is your PC on the same subnet as the PLC (10.2.5.xxx)? Also, are you plugged into the correct Ethernet port on the PLC? Are you using an Ethernet hub or a crossover cable?
  8. TA timers need to be Reset manually. They do not reset automatically when power is applied as TD timers do. Put in a reset and your TA5 current will be correct.
  9. It's actually the exact opposite. The router is set to forward port 20256 from their public IP address (WAN) to their to their private IP address (LAN). This is actually fairly common, and while it's not secure, it's generally okay because there is little incentive (profit motive) to hack in these situations. Tensions in the ME provided the incentive absent a profit motive. It's a good lesson learned here - avoid using default settings.
  10. Saw a report on ABC News this morning about a drinking water pumping station in Pennsylvania being hacked. The photo was clearly a Unitronics V570 PLC. Unitronics, among others, is being targeted and we need to be acting immediately to prevent more occurrences. We need some guidance from Unitronics right away.
  11. True, but I'm having difficulty imagining another point of attack. If there is, then Unitronics can circumvent with a firmware upgrade.
  12. @Cara Bereck Levy, I don't see anything in the Help file that indicates exactly what special characters are allowed or disallowed for the PLC Name. Since this is essentially the password for remote communications, could we get this spelled out so that we can take the appropriate action to secure PLCs in the field? Thanks.
  13. Maybe this will be useful: https://www.plcdev.com/using_ladder_logic_for_gray_code_conversion
  14. Also, not sure what you're trying to say here. The PLC program does not reside on the SD card. You can upload or download a program to or from an SD card, but that requires some PLC code to make that function.
  15. I recommend you use a different socket and port # for your communications with the external device. The reason for that is that the standard PC to PLC communications uses port 20256, and socket 1 defaults to that for you. While that is only the default, and you can change things in VisiLogic to use any port you want, there is no reason not to keep this as simple as possible while you're learning. Use socket 2 or 3 and set it to an appropriate port # for your external device. It doesn't hurt to go ahead and initialize socket 1 to port 20256 and set to server (slave) for your PC-PLC comms using VisiLogic over ethernet.
  16. I don't know if it's related, but I was having a similar problem when Pinging an IP address from Windows. I've discovered that in Ping, when using a leading zero it interprets the number as hex rather than decimal. Seems silly to me, but true nevertheless.
  17. Yes, everyone knows that Marvin the Martian wants to wipe out Earthlings. The forum is just doing its part to spread awareness. 🤣
  18. The engineer's creed (and my personal mantra): "If it ain't broke, don't fix it".
  19. Swap out the Function blocks for the ones under "PID Autotune".
  20. I went ahead a wrote a little routine that should show you how to do some of the stuff you're wanting to do. I did this quickly without testing, so I likely made a few mistakes, but you should be able to get the concept. Let me know if you have questions. Data Table Help - BL.vlp
  21. This really makes a ton of sense. Thanks for the great research and analysis.
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