[Fix 11.2.4] SCS not seeing all com ports

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jboerst
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Joined: Mon Sep 22, 2008 1:11 pm

[Fix 11.2.4] SCS not seeing all com ports

Post by jboerst » Wed Sep 25, 2013 2:08 am

I have installed a USB to 8x serial adapter. Device manager shows all 8 com ports 4 thru 11
Com 4 works fine. SCS only gives me the option to select Com 1 or Com 4.
Any Suggestions?
I am using most recent version of SCS running windows XP

Mike Daniell
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Re: SCS not seeing all com ports

Post by Mike Daniell » Wed Sep 25, 2013 6:11 am

SCS currently only checks the first 4 COM ports, ie COM1 - COM4, but there is a reason for this!

To check for the availability of COM ports, SCS calls a Windows API function CreateFile(Com1, ...) for COM1, and similarly for COM2 etc. If the function returns -1 then the COM port is not available. What I found when coding this was that for COM1 - COM4 the function returned a result 'instantly' but for COM5 onwards the function would take about 3 seconds per port.

However, I've just run a quick test on my Windows 8 machine testing for COM1 - COM8 and the entire checking for those 8 COM ports took only about 1ms. So I can certainly now increase the range, but I'll repeat the test under earlier Windows versions (including XP) to see if the range still needs to be limited to 4 ports for older Windows versions.

Meanwhile, do you need more than 4 COM ports, or is there any reason why you would need to use COM5 or higher?
Mike Daniell
Show Cue Systems Pty Ltd
mike@showcuesystems.com
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jboerst
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Joined: Mon Sep 22, 2008 1:11 pm

Re: SCS not seeing all com ports

Post by jboerst » Thu Sep 26, 2013 9:15 am

Thanks Mike.
Still getting my feet wet on all things RS232
My computer recognizes com1 and com4. Not sure what Com2 & 3 are doing.
Don't see them anywhere. I finally got a different program to recognize all Com ports
Not sure if I need all these com ports or not.I am trying to control multiple devices.
Thanks again

Mike Daniell
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Re: SCS not seeing all com ports

Post by Mike Daniell » Thu Oct 03, 2013 9:26 am

Fix ready for 11.2.4. SCS now checks serial ports COM1 - COM16.
Mike Daniell
Show Cue Systems Pty Ltd
mike@showcuesystems.com
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Mike Daniell
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Posts: 3632
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Location: Brisbane, Queensland, Australia. TZ:GMT+10
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Re: [Fix 11.2.4] SCS not seeing all com ports

Post by Mike Daniell » Tue Oct 15, 2013 10:28 am

Fix applied in 11.2.4 - now checking COM1 - COM32.
Mike Daniell
Show Cue Systems Pty Ltd
mike@showcuesystems.com
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