drewh Posted May 1, 2012 Report Share Posted May 1, 2012 Is there a reason I cannot connect to a PLC beyond COM16(via Visilogics or .NET driver)? Thanks for your help. Quote Link to comment Share on other sites More sharing options...
AlexUT Posted May 2, 2012 Report Share Posted May 2, 2012 Hi, VB limits number of COM ports to 16. So VisiLogic and VB Communication Driver have the same limit - 16 COM ports. Last dotNet driver will use up to 256 COM ports. You can download it from unitronics Support site: Unitronics.ComDriver Compiled Binaries Ver_1.0.0.47.zip Quote Link to comment Share on other sites More sharing options...
drewh Posted May 2, 2012 Author Report Share Posted May 2, 2012 Hi, VB limits number of COM ports to 16. So VisiLogic and VB Communication Driver have the same limit - 16 COM ports. Last dotNet driver will use up to 256 COM ports. You can download it from unitronics Support site: Unitronics.ComDriver Compiled Binaries Ver_1.0.0.47.zip Hi Alex thanks for your help. Is there a reason 256 is the hard limit? Thanks again. Quote Link to comment Share on other sites More sharing options...
Emil Posted May 2, 2012 Report Share Posted May 2, 2012 Hi, Do you have a real project, where you need more than 255 controllers, or this is just a question of curiosity? If you have a real project and 255 COM ports are not enough, please contact Unitronics Tech support team at support@unitronics.com with description of the project and the needs. Despite this is very specific, unusual request, we will see how we can help you. Quote Link to comment Share on other sites More sharing options...
drewh Posted May 2, 2012 Author Report Share Posted May 2, 2012 Hi, Do you have a real project, where you need more than 255 controllers, or this is just a question of curiosity? If you have a real project and 255 COM ports are not enough, please contact Unitronics Tech support team at support@unitronics.com with description of the project and the needs. Despite this is very specific, unusual request, we will see how we can help you. Yes. We're(at my company) using Unitronics plc's in conjunction with Digi's(www.digi.com) realport driver to communicate with hundreds of locations. At this point we're having to create a new box(virtualized) for every 16 locations. Although 256 is still a lot better than every 16. I will be contacting shortly. On a side note after downloading the latest .NET driver, I still can't communicate via COM17. Thanks for your help. Quote Link to comment Share on other sites More sharing options...
Saragani Posted May 3, 2012 Report Share Posted May 3, 2012 Please see: http://support.microsoft.com/kb/100111 http://digital.ni.com/public.nsf/allkb/F7A9002D7B8E31E7862568D6006BD10B Windows (at least up to Windows XP) is limited up to 256... I'm not sure though about Windows Vista and 7, but the communication driver is build for maximum compatibility. About not being able to communicate with the PLC while using COM117, Please check the cables and confirm that both the PLC is connected to COM117 and that the program is trying to open the connection on COM117. If you are still not able to trace the problem, there are ways to sniff or log the communication in order to see what's the problem. Please confirm that your .Net program works when you try to work with for example COM1 or COM17 before starting to check it with COM117. Quote Link to comment Share on other sites More sharing options...
drewh Posted May 3, 2012 Author Report Share Posted May 3, 2012 Please see: http://support.microsoft.com/kb/100111 http://digital.ni.co...62568D6006BD10B Windows (at least up to Windows XP) is limited up to 256... I'm not sure though about Windows Vista and 7, but the communication driver is build for maximum compatibility. About not being able to communicate with the PLC while using COM117, Please check the cables and confirm that both the PLC is connected to COM117 and that the program is trying to open the connection on COM117. If you are still not able to trace the problem, there are ways to sniff or log the communication in order to see what's the problem. Please confirm that your .Net program works when you try to work with for example COM1 or COM17 before starting to check it with COM117. Hi thanks for your help. I'm able to communicate past 16 now. It was a simple issue. I'm guessing I can add to the enum object in the source code for COM ports past 255. I'll try that and see if it works on Windows Server 2008 R2/Windows 7 Quote Link to comment Share on other sites More sharing options...
Saragani Posted May 3, 2012 Report Share Posted May 3, 2012 Hi, the Com enum was for easy configuration. However, when it was created, we allowed only up to 48 ports, and we have increased the num of ports to 256 only recently. Since you have the code, then you can easily change it so it will not work with enum but with a ushort. This way you will be able to enter the port number as a number up to 65535 and when needed create a serial port with port-name = "COM" + portnumber Quote Link to comment Share on other sites More sharing options...
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