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Isakovic last won the day on June 14

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  1. The way that Sargani explained in post number 2 should work. Yes you can (and should in this case) read several registers in a row. If in "Modbus Master" setup you define tag as an array of 16 bit integers, let's say of length 10, PLC will read 10 consecutive registers from Modbus Slave. Can you post part of the program with code for making 32 bit float from 16 bit ints, with setup for Modbus so we can help you find the problem?
  2. Hello, I need to add two columns to an existing Data Table, in VisiLogic this can be done without losing values, I'm not sure how it works in UniLogic, I remember once editing it and all values went to 0. Can I add a member to Data Table struct and retaining values in old columns? I would back up old table, but problem is that I can't read the values in online mode and back them up, I get this error: Connection to plc was over Ethernet, ladder works normally in online mode so I wouldn't say it's a connection issue. If new columns cannot be added without losing values, my se
  3. I like your style. It's more efficient, I have separate bit for every Modbus command. Will give this method a try.
  4. I'll explain the problem I had, maybe it helps somebody. I have several controllers that need to have synchronized RTC, and there was a problem that time update didn't work properly. After some troubleshooting I found that "Status" variables need to be defined in order for function blocks to work. This does not work (usually): This does work: Both cases compile the same without error or warning. UniLogic version 1.28.34 PLC USP-070-B08
  5. Here are my suggestions. This part here: If no connection is established due to some reason, T0 will stay on and PLC will not try to reconnect again. T0 should restart if there is no connection after some time. Since you do both master and slave pack all registers that you need to read from slave one after another and then read them all at once with one command (Vector length 24 in read command). It's more efficient than reading them one by one. About SB168 I always Set it at startup as suggested and Set SI103-106 to 200. Don't know how it behaves if values are left bl
  6. I suppose this is because of differences in how memory is organized in Visi and Uni. But if it can be done it would be great.
  7. This could have inspired that Note. I remember reading an old topic about user objecting that timers which have unused contacts should generate warning message after compiling, now timers with unused contacts do generate warning after compiling.
  8. When doing system upgrade for Vision PLC, there is a message while OS is being installed: For System Upgrade PC should be connected to PLC via COM 1 Should be, or has to be? OS can also be upgraded vie Ethernet, so why is it recommended to be done over serial port? Why is this note there? Is it technical reason or practical, like if something goes wrong PLC will be in your reach and you won't have bricked unit in remote location.
  9. I'm not sure about reinitializing Configuration FB. It does have addresses for only 15 slaves, but if I remember right when you execute read command it will read from whichever slave the PLC is connected to, disregarding the "Slave ID number" that is in the read command. Maybe this was an issue from some older VisiLogic version when I encountered this for the first time. I've wanted to test this for some time now, but don't have the will. So, I tested this. One master reading 3 slaves one after another from the same Socket. No slaves were defined, every read command had Slave 0
  10. I'll tell what worked for me regarding your questions, newbie88. Steps go as you described. Connect to 1-Read-Disconnect; Connect to 2-Read-Disconnect... You are using TCP so connection is required. Delay of 0.4 seconds after disconnecting from one client before connecting to second one, and another 0.4 seconds before sending Modbus commands, maybe this can be shorter (probably, you should experiment). For 4 clients this cycle takes 3.9 seconds, if time is critical you may need to use more sockets or go to UniStream. For any slave that drops number of retries and timeout will add extra d
  11. Great topic. I have a question for eminent wizard kratmel. Is it recommended or not to use different power supplies for main power and output power? If both are referenced to ground I guess not, but what if they are floating? I remember a case when I had safety circuit cut +VO line as a bonus security on Jazz unit. This rebooted PLC when activated so I don't use it anymore. Why was this happening? It was the same supply for PLC and outputs.
  12. Yea, this last version is a little messy. Status 19 means that the socket is initialized properly, when it connects it changes value to 23. Change those port numbers and separate rungs as Flx said and tell us how it goes. If you need to connect from a PC over Ethernet just initialize one socket as TCP slave.
  13. Your best option is to contact the company/person that made the original program. If that is not an option contact Unitronics support directly. Or write program from scratch. If you can't get your hands on the program this is probably what has to be done.
  14. 1. You have correctly initialized Socket 3. What is the purpose of MB11? Looks to me like it has to be switched on manually. Also it is better to call "Socket Connect" block over transition contact. Maybe something like this: It will reconnect after losing connection. In rung 3 you are closing socket after Modbus command, you don't need to do that. Maybe socket status changes to other value than 23 while sending Modbus command and may trigger connect block if it stays like that for more than 5 seconds in this example. You may have to investigate this. Also look into "Keep alive"
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