Disappearing Windows 10 serial port issue

[Greg1956]

Hi,

I have a compiled program in LV2016 which utilises a serial connection via Com1 to a flow meter.

Occasionally at startup it can't find/access the COM1 port.

When I run NI-Max 18.5 to check/configure the port it says it exists but it can't access it.

If I unistall COM1 via the Device manager and restart the PC  it returns and all is good.

So is it me, Windows 10 or Labview that is having the issue??

I'm running Win10 build 1809, LV2016 f6 runtime, NI-Visa 18.5, NI Serial engine 2018, NI-DAQmx 18.5.

thanks

Greg

[Greg1956]

Hi,

I have a compiled program in LV2016 which utilises a serial connection via Com1 to a flow meter.

Occasionally at startup it can't find/access the COM1 port.

When I run NI-Max 18.5 to check/configure the port it says it exists but it can't access it.

If I unistall COM1 via the Device manager and restart the PC  it returns and all is good.

So is it me, Windows 10 or Labview that is having the issue??

I'm running Win10 build 1809, LV2016 f6 runtime, NI-Visa 18.5, NI Serial engine 2018, NI-DAQmx 18.5.

thanks

Greg

[crossrulz]

What adapter are you using for your serial port?  Are you trying to use it with another application?  It could also be Windows turning off the USB hub the adapter is attached to as a "power saving feature".  You can turn that off in the Device Manager.

Unless it is an NI adapter, you do not need NI-Serial.

[Greg1956]

No adapter is used.

I'm using a Dell 3060 small form factor which comes with a serial connector attached.

OK, I found that I had to install NI-Serial so I could see and configure the serial port in NI-Max otherwise it was not visible at all.

thanks

Greg

[crossrulz]

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@Greg1956 wrote:

OK, I found that I had to install NI-Serial so I could see and configure the serial port in NI-Max otherwise it was not visible at all.

---

It was probably VISA you didn't have installed.

I have yet to have a built-in serial port fail to work for me.  There might be a driver issue.

[Greg1956]

Thanks,

had a talk to Dell as well, as it could be 1 of 3 things.

PC hardware

Windows 10

Labview software.

So I now have a list from Dell to try.

And I will see if this fixes it, I came to this as I found that an older Dell model had serial port issues.

So I'm attacking the problem from several fronts.

thanks

Greg

[billko]

LOL that's like saying the car won't start because of:

• The engine, or
• The electrical system

Sorry, I'm not meaning to make light of your problem, just the silly list that they gave you.

Maybe it's a flaky serial port?  Maybe you can install a serial port card and see?

Is it a real serial port, or a USB adapter in disguise?  I've seen USB to RS-232 adapters hidden from the users, with only the DB9 port visible.

[Greg1956]

Hi,

just a simple divide and conquer approach to identify the culprit.

Oh yes, it is a physical DB9 Serial port on a Dell 3060 small form factor box.

Believe me when I say I was working when PCs were first introduced into industries as an alternative to large main frames..

And I have avoided usb to serial cables as they seem to have issues with Windows 10,as Microsoft is trying to force us to stop using them.

So I'm checking on 3 fronts to see if this has appeared here as well.

The previous incarnation that I used was on LV8.6 on a Windows 7 PC (2010 vintage) and worked faultlessly.

This one is a new PC, Windows 10 and LV2016, too many changes in one hit I think.

But I will get back to the forum if there is a solution.

Anyway back to dinner.

Greg

[billko]

---

@Greg1956 wrote:

Hi,

just a simple divide and conquer approach to identify the culprit.

Oh yes, it is a physical DB9 Serial port on a Dell 3060 small form factor box.

Believe me when I say I was working when PCs were first introduced into industries as an alternative to large main frames..

And I have avoided usb to serial cables as they seem to have issues with Windows 10,as Microsoft is trying to force us to stop using them.

So I'm checking on 3 fronts to see if this has appeared here as well.

The previous incarnation that I used was on LV8.6 on a Windows 7 PC (2010 vintage) and worked faultlessly.

This one is a new PC, Windows 10 and LV2016, too many changes in one hit I think.

But I will get back to the forum if there is a solution.

Anyway back to dinner.

Greg

---

I was working with the team responsible for the introduction of the IBM PS/2 series.  😉

[RTSLVU]

---

@Greg1956 wrote:

Occasionally at startup it can't find/access the COM1 port.

When I run NI-Max 18.5 to check/configure the port it says it exists but it can't access it.

This is usually indicative of something else (another program) having control of the Com port. I believe even LabVIEW can cause MAX to display this if you are not closing your VISA sessions properly.

Make sure there is no Dell  software of any kind running. My company buys Dell and even "corporate" Dell's come with all kinds of bloatware preinstalled. Mainly Dell system managers, update checkers, and service programs that inventory your system can cause this because they access all of the ports when they take inventory. 

Now that I think about it I recall having an issue with Intel RST software using a com port on one of my machines. Not sure what Intel RST needs a com port for, I am guessing it's just a debug output. So it does not complain if the port is already taken by another program. You might have some kind of race going on as to who gets to the com port first.

[RTSLVU]

Occasionally at startup it can't find/access the COM1 port.

When I run NI-Max 18.5 to check/configure the port it says it exists but it can't access it.

[Greg1956]

Thanks,

got some work to do with all these checks

Will uninstall Dell updater after I complete the driver updates and look out for Intel RST.

Yes IBM PS/2-50s were the PCs controlling our Steel analysis equipment, good reliable boxes.

See I go, thanks again.