12/15/2009 1:42 PM | |
Joined: 10/7/2005 Last visit: 10/6/2024 Posts: 3024 Rating: (1054)
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Hello again ALU just one last idea. The guys from B&B electronics pride themselves on their RS485 Know How (and rightly so) and it wouldn't hurt tosend them a quick enquiry E-Mail. Good luck and please let us know the outcome. |
Cheers |
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This contribution was helpful to1 thankful Users |
12/17/2009 3:15 AM | |
Posts: 35 Rating: (0) |
Hi fritz, regret to say, I sent mail to B&B electronics but 3 days gone with no answer back, however, i got some document from their site... I trying to sovle....in this case, do you think that using the Repeater will help or not? I think about it but I also think that the bad solution... cannot guarantee it will help or not.. |
12/17/2009 12:04 PM | |
Joined: 10/7/2005 Last visit: 10/6/2024 Posts: 3024 Rating: (1054)
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Hello ALU repeaters certainly never "hurt" and in your case may very well create a stable network by virtue of "breaking" the bus into smaller segments as well as isolating the segments from each other (as far as I know all RS485 nowadays will be isolating repeaters but please check this before you decide to buy one). Having said that, we know the following is true about your network: 1.) It works with 5 devices and only 100m overall cable lenght 2.) It Does NOT workwith5 devices and >250m overall cable lenght 3.) It SHOULD workwith up to 31 Devices and up to 1200m overall cable lenght As such - and assuming that installing repeaters will fix it - putting repeaters in will only deal with the symptons rather than eliminating the root cause (it's a bit like constantly taking painkiller pills for a persitent toothache when you know that you really should go and seea Dentist). Personally I'd rather find out what is really wrong. FYI, there are some really nice USB based Oscilloscopes available which would not only be useful for you to have now butwill always come in handy for all sorts of taks. One example (and one that I've used for a long time to verify Profibus signals before Profitrace 2 came out) is the Handyscope from Tie Pie Engineering and you can find out more about it HERE. I hope this helps |
Cheers |
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12/18/2009 4:53 PM | |
Joined: 1/17/2007 Last visit: 9/30/2024 Posts: 1546 Rating: (537) |
ALU, I came across this information on my travels around the internet. It is a very good article and might prove useful. RS485 Article |
Programming today is the race between software engineers building bigger and better idiot proof programs, and the universe producing bigger and better idiots. |
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This contribution was helpful to1 thankful Users |
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