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Topic: Slow PortOpen response
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| By: Geoff Engelstein | Posted on: Nov 14 2015 at 04:46:11 PM | I am evaluating SCOMM32 to fix a Windows 10 incompatibility.
On the development system (running Windows XP) I am getting extremely slow response to the PortOpen call.
I have a routine that initially scans CommPorts 1-64 to find which ones are available. With MSCOMM32 I was using an error trap to detect the missing ports, and it worked very quickly.
Here is my code under SCOMM32:
With wwMDI!comMain
For i = 1 To 64
Debug.Print i
.CommPort = i
If .CommName > "" Then
If s > "" Then s = s & "|"
s = s & str$(i)
End If
Next i
End With
It is taking approximately 6 seconds to execute the ".CommPort=i" statement. So for 64 ports it takes about 6 minutes, which is way, way too long.
As I noted, this was never an issue under MSCOMM32.
A few other things: The scomm32 control is located on an MDI form. And the 6 second time is the same whether the port exists or doesn't exist.
Any thoughts? | |
| By: Support | Posted on: Nov 14 2015 at 09:58:45 PM | Getting the full friendly name of the com port is a little slower so looping through 64 ports might take a little while. But certainly not 6 seconds per port.
But just executing .CommPort=i really should not take 6 seconds.
Ignoring the friendly name and all the other code - Are you saying it takes 6 seconds just to execute .CommPort=i
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| By: Geoff Engelstein | Posted on: Nov 15 2015 at 08:23:49 PM | Yes - I stepped through the code and it takes 6 seconds to execute that command.
I am also (and I should have mentioned this before) running inside an Oracle VM virtual machine. However running MSCOMM32, also inside the same virtual machine, is virtually instantaneous.
I will try running outside the virtual machine to eliminate that from the equation. | |
| By: Support | Posted on: Nov 15 2015 at 10:02:59 PM | Personally I do a lot of development work in VMs. VMWare on Windows 10. VirtualBox and Parallels on OSX. I like testing in various operating systems and VMs are a great way to do that - so if there was a 6 second delay, even when working in a VM, i hope i would have noticed it.
At he moment i can't explain it. I'll trst it tomorrow just to see if I can reproduce the problem.
Having said that. You're the first person to ever report this problem so I'm hoping i dont find a problem. | |
| By: Support | Posted on: Nov 18 2015 at 07:20:59 PM | Sorry about the delay coming back to this thread - I've tested this over a few days with my usual VM's and I just can't reproduce the problem.
If you could test outside of your VM it would be interesting to here your feedback. | |
| By: Guest | Posted on: Nov 29 2015 at 08:39:09 PM | | I see the same using a reg. version 8, very slow on vista/64 causes software to hang. mscomm is fine on vista but mscomm32 wont work on win10. | |
| By: Support | Posted on: Nov 30 2015 at 09:57:06 PM | To:- Guest who posted on Nov 29.
Are you also using virtual machine?
What programming language are you using? VB6? Would you be able to make a small project that exhibits this problem. No fancy UI. Just a form with a button that sets up and opens/closes a port.
If you can do that then please zip it and email it us
support at comm32.com
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| By: Support | Posted on: Dec 7 2015 at 10:19:54 AM | I've tested this on 64bit Win8 and Win10. Also in various VMs. VMWare, Virtual Box and Even Parellels on a Mac and just can't reproduce the problem. If 'anyone' has this problem and can make a small project that exhibits the problem and zip it and email the project to us.
Also, anyone with the problem can tell us what serial ports they're using?
Thank you
support at comm32 dot com | |
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