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  1. Past Hour
  2. Why does ML/1400 send a TCP [RST] ?

    Mark, See whether you go with this idea, but I think there's a more obvious answer. I've just realised that the List Identity is being sent as a UDP datagram. As such, there's no way it is ever going to act as a keep-alive for the TCP session ! It doesn't explain why the ML1400 is only waiting 17 seconds before it issues the RST, but I can worry about that later. Do you agree ? Gary  
  3. Today
  4. Why does ML/1400 send a TCP [RST] ?

    I was going to write a bunch of stuff but decided at least one more test was needed. With no other connection to the PLC, issue the register session and forward open. Then doing nothing. How long before the PLC drops the connection?  
  5. What is your favorite and least favorite HMI software?

    Just noticed this comment.  Yes RedLion products are in wide use here in the US.  They are my goto for HMI (and yes free software but not my major concern) and they also own Ntron switches which I have been using exclusively for years. I gotta say, my work is all done in the industrial sector.  Paying for good software is not a big issue to me.  Paying $500 or $5000 for a piece of software that is going to be used on a $10 million dollar line doesn't seem a big issue to me as long as it is a good solution for the line.  There are too many people in the industrial world that treat things like this as if it was a personal expense.  If I can save an hour of downtime with quality software in an industrial environment, then I have generally paid for the software.  Just a thought.  Different mindset is necessary.
  6. Thank you for the help. I guess I can make it with one big array of boolean(3840) and fill the D memory chronologically with 64 so I can get the bits in the array with the right order. And then I can reorder them as I wish.
  7. Hi all, I have my own driver to communicate with a MicroLogix 1400. Please refer to the attached screenshot from Wireshark. is my driver's host, and is the ML1400. The startup sequence to establish a connection & session with the PLC is correct I believe: - In the grey highlight, client requests a connection to .192 via SYN and this is ack'd - A session is registered, and forward open is successful - There's a lot of stuff in green simply because I've also got an HTTP browser session open to the PLC to monitor its session table - In between, spaced 8 seconds apart, are my two attempts to keep the connection alive by sending a List Identity request (as a ping, if you like). These are highlighted in pale blue. - However, 16.5 seconds from the start of the grey highlight, and 16.4 seconds after sequence=115 ack=99, the controller sends back a [RST, ACK] and a callback from my socket code tells me that the session has been dropped. The connection timeout for the PLC is configured as either 30 or 60 seconds, so I don't see how that's relevant here when the reset is happening only 17 seconds after it was established ? However, presumably the PLC doesn't see the application-level "List Identity" request as a valid means of keeping the connection alive. What is the correct mechanism to use that the PLC will accept as a keep-alive ?
  8. ViewPoint

    Hello, I created a HMI application and created the ViewPoint displays and then the runtime. When I type the IP address in the browser I get an error "Can't reach this page"but I can see the HMI in RSlinx. Does anybody had this problem before? Thank you. 
  9. How create global objects for many devices (GT Designer 3)

    Hello everyone Is it possible to use this multiplexing function (Offset) connecting a GOT2000 to my drives directly? I ask cause  my drive's Faceplate  uses I/O  like X0001, Does anyone have any idea of how to implement it that way? Thank you in advance.
  10. Thank you very much for the help! For the link too. It is very nice when there are people like you who help!
  11. Apologies Michael, You are correct. 
  12. Weird Timer Behaviour

    I have already found the answer. I set the timer.PT value with the use of an INT which I convert to TIME at the beginning of every cycle. This means that PT would still be 0 when the timer would start. This causes Q to true immediately.
  13. Connect to an AB Logix5555 via 1756-ENBT?

    Ok guys i start to see some light at the end of the tunel. i call the rockwell support and the said i schould first  make sure i have Gateway Version of rslinx installed, since i want to make a remote connexion.  Then i use this link to correctly set up DCOM on remote and Client PC. On the Client PC i can read the data on MatrikonOPC Explorer but not on MATLAB. Attempting to connect to remote OPCServer with matlab using OPCServerinfo('') will not work and the error says either "ACCESS DENIED". or "error in security package"  
  14. Weird Timer Behaviour

    Hello, I've been using a Beckhoff PLC and TwinCAT3 lately and I'm learning how it all works. Currently I'm using a ton timer in my program and I've noticed some weird behaviour. The timer.IN is set to true and afterwards I check for timer.Q in an IF statement. That statement should therefore only be true after the timer.PT delay value. However, the first time after I activate the configuration and timer.IN is set to true, timer.Q is immediately set to true for a very short amount of time. When I reset all values and try again without reactivating the configuration, this doesn't happen. I'm thinking that I don't initialse the timer in the correct way or something along those line. I have attached a code snippet. The problem I'm encountering is that the first time after I have activated the configuration and the tonTimeout.In is true. The following IF statement is also true without having run for the delay time. This sends my program to an error state. However, after resetting the values this doesnt happen anymore. Can anyone help me with this matter?
  15. Indusoft Web Studio

    i am using indusoft web studio for the modbus logging. program runs successfully but after a half day or a day it shows error " error initializing the driver modbu 10.10: invalid serial port "any suggestion will be appreciated.RegardsZubair Ahmed
  16. FX0N doesn't have a retentive timer so i used a pulse bit instead. Y0 en Y1 represent the actions If you want to learn more about PLC programming:  
  17. QJ71C24N 7F68 Framing Error

    That's strange why not hook up hercules to the PC and check it. Maybe it will give a hint into what different between what you've send and what's actually being received
  18. Yesterday
  19. You can reference the index of the structure with a variable IF you give the structure an address in the symbol table.      
  20. Bit access in Words in CX-Programmer using structured text

    It won't let you use a variable for the index of the bits when it is a structure.  This is ok: In.CheckLWord[4] This is not: In.CheckLword[j] Not sure why, but that is how it is.  CXP will only let you use variable indexes for arrays and apparently it does not recognize an array of an array. The unexpected syntax will go away after this issue is resolved.   Sorry.  
  21. scale instruction in Q series PLC?

    Dude, when you reply to some tread you need to pay attention in the date, this tread is 12 years old.
  22. PN PLC 2 PLC multiple DB's

    The "right" way may depend on who you're talking to... There may not be a way to send multiple DBs with a single connection. Have you tried Siemens tech support? At least in North America, they're pretty easy (and free) to contact. They haven't always been the most helpful, but they're available.
  23. Factorytalk password

    That squares with my experience. We were repeatedly tasked with changing the passwords in a series of machines that all used the built-in runtime security system, which required going out to the machines (about 20 or so total HMIs), editing the project, and downloading it. It was an all-day task that we really didn't have time for. I spent a couple of days figuring out how to let them change their own passwords (very easy) and backup/restore them so we could make runtime changes at will (a lot more complicated). When we investigated doing that to the PV+ HMIs, we found out from tech support that the current password is stored in the MER file inside the HMI, so if we wanted to keep the passwords after making our changes, we would have to upload the existing MER from the HMI and restore it into View Studio. We wouldn't be able to use our APA project backups at all. I'd say to change from using the built-in user administration in the PV+ to using a number stored in the PLC. Make sure you're OK with anyone who can get into the PLC having access to the passwords, though. Then write either a pseudo-random calculation or look-up table.
  24. PN PLC 2 PLC multiple DB's

    That's right. I just made a quick Move block function "POKE_BLK" and merged the different unit data to this DB. But Wold still like to know how the "right" way is o send multiple DB's over a single connection.
  25. Factorytalk password

    I don't think so, it's either in the PLC with macros in the HMI or use the built in security functions of the HMI. To clarify, the user name and passwords are based upon the Microsoft security.  The HMI does have an ability to change the password, but it is a manual intervention and only applicable to the application running on the HMI (i.e. the MER).  It won't even be the same when compared tot he project within FactoryTalk View ME. So, if you want something that is random and automatic, you'll probably want to do it in the PLC.
  26. QJ71C24N 7F68 Framing Error

    Also, Gambit, is there any reason that you can think of as to why the trace data shows the correct hex but the printer is receiving erroneous data?   Thanks
  27. QJ71C24N 7F68 Framing Error

    Thanks.  Hercules worked great.  I was able to send HEX data to the printer to generate the label just fine.  So my issue is on the PLC side.  For some reason my data is being converted to zeros and sent to the printer.  I'm trying to solve that issue now.   Thanks Gambit
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