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dierkens

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  1. Make sure the correct MS Windows .net files are installed.
  2. Once that register is set to a value it will continue to have that value until something else acts on it. You have two choices; you can either clear the register on a timed basis, perhaps just before the other PLC sets it, or you can have a routine that 'pings' or keeps track of the communication between the two. This can be in the form of a heart beat setup where one PLCs set a register to the a 1; the other sets sit a 0 and then if the heart beat stops you know the comms has gone down. There are a ton of ways to go about it.
  3. I know this is an old topic, but I wanted to see if there's been any movement on having a 2nd network port available for things like MODBUS/TCP? Right now it's quite a bit of work to get these PLCs onto two (2) networks without having the OT Network group freak out over network security issues.
  4. Does anyone have any tips on getting hardware? We've been waiting 348 days to get UID-1600: 5 UID-0016R: 5 When asked, we keep getting the 'it should be on it's way any day now'. We've got other projects coming up and I'm trying to avoid these long delays.
  5. Make sure you're using the same version number of the Unilogic program as that used in the PLC. That's where I'd start; just to make sure there aren't any version mismatch issues.
  6. Why not just use MODBUS status for everything you only need current state updates on and then have the other PLCs just read/write stuff to each other as needed?
  7. You can use the periodic reads. play around with it and figure out what method(s) work best with the PLC you’re using.
  8. You don't have the project opened anywhere else do you? Verify that all of the files are closed on any other machine.
  9. Does anyone know if this floating point swapped or float inverse has been implemented?
  10. Quick question that I've been asked about a few times by clients and other controls engineers that I have a 'hard time' answering. We assign an IP Address to both the CPU and the HMI but we only ever use the HMI Address for anything such as MODBUS/TCP communications, VNC, FTP, etc. What's the purpose of the CPU IP Address if we never use it for anything? It' nice that the 2 ports are actually into a switch but if we can't really use the other IP Address then what's it for? This tends to come up when we need to communicate/access the PLC over different networks.
  11. dierkens

    Vic

    I don’t understand the ‘use of replacement’ and the need for UDP in regards to MODBUS. Can you outline this please.
  12. 1). Save your data table more frequently. Hint: you can’t save data in a time frame that exceeds the update rate. The file saving process takes a few seconds at minimum. In our case we were saving 1-minute data and it was taking 61-seconds to save it. That’s not good. 2). Watch your file status bits and address errors asap. 3). If this data is critical, then you should at a minimum take screen shots or a cell video to capture the data and manually process later. 4). Without adding new logic I don’t believe you can save this dataset. As soon as you add logic that DT is probably gone, but then again I don’t know that I’ve looked up if DT’s are retentive.
  13. I know this is an old post but we're having a similar problem and wanted to know if the OP ever resolved this issue. We've got it setup in an engineering office with no high power sources nearby. The signal wires placed into another device don't show this fluctuation at all. If I don't get a response I'll create a new post.
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