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5/26/2009 2:23 PM | |
Joined: 1/29/2006 Last visit: 9/11/2024 Posts: 446 Rating: (64) |
Hey, mynamesnotnick ! I believe, the "catch" lies in re-definition of your DB1. You said, you have added something in this DB. After downloading of this nevely defined DB1,on-line values wereover-written with default values for this DB! In my opinion, it is not a good practice to chaneg definition of DBs, if they are alllready in use. In any case, you must be very(!) carefull, when doing that. Have fun! uel123 |
5/26/2009 6:35 PM | |
Joined: 1/29/2006 Last visit: 9/11/2024 Posts: 446 Rating: (64) |
Hm, very strange.... . I have not heard yet, that value in DB would be changed by itself without any reason... (OK, may be in case of some serious system disturbance, EMC discharge or something like that...) . When you changed your DB1, what did you do? Did you add something at the beginning, in the middle or at the end of "old" DB1? Do you use "Recipes" on your HMI,with data from this specific DB?
No, I don´t mean that. I only said, that you have to be careful, when doing that. If you add things at the end, let say it is OK (exceptat DownLoad, when default settings are written to on line DB...). But if you add things at the beginnig and/or in the middle of Data block, keep in mind, that you are changing the structure od DB and that all accesses to data in data block have to be checked, through all user program (and also HMI program)! have fun! uel123 P.S.: there was allready a discussion about proper methods, how to "expand" existing DB without too much pain. See this: /tf/WW/en/Posts/13638#top |
Last edited by: uel123 at: 5/26/2009 6:48 PM |
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5/26/2009 11:23 PM | |
Joined: 10/10/2007 Last visit: 4/25/2024 Posts: 20 Rating: (3) |
Hiuel123 Thanks for the link.
I'm working in LAD, using only symbolics, never absolute addressing.
Yes, I have a single recipe (with multiple data records). The default recipe values for the addresses that were lost are not zero. I have had this type of behaviour (memory values changed unexpectedly) once before, when changed the INs and OUTs of some FBs. That is why I was so careful this time. thanks
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