Where the Com Port coming from?

[Grey]

Hi All,

I'm using laptop which has no serial port but only has the parallel port in it.

The windows device manager is showing one Serial port and one parallel port.

The MAX also showing one serial and one parallel.

my query is that i do not have the serial port physically but why the device manage rand MAX showing the com Port?

I asked my IT guy about it and he said by default during windows installation it happens like that.

and i do not know what i can proceed further. i'm thinking to buy a USB to serial Port converter so that i can try to communicate the device from the laptop.

Please find the attachments.

Edited April 11, 2012 by Grey

[hooovahh]

I asked my IT guy about it and he said by default during windows installation it happens like that.

and i do not know what i can proceed further. i'm thinking to buy a USB to serial Port converter so that i can try to communicate the device from the laptop.

Your IT guy was wrong. If Windows Device Manager sees a serial port, its because there is a serial port. This may not be a normal serial port that is exposed to the outside world via a DB-9 but an internal one for diagnostic support. I've seen several PCs have internal serial ports that allows for for intimate access to the PC, or it is possibly a serial port that is only accessible through a dock that the laptop is connected to.

In any case it is not going to be a serial port that is going to be available for communicating with other hardware and investing in a USB-to-RS-232 is going to be a good idea. I've heard some cheap ones don't work with all hardware, but I haven't found any hardware my no name cheapo couldn't talk to yet.

[Rolf Kalbermatter]

Does your notebook happen to have a built in modem? That is usually installed as serial port too.

I've heard some cheap ones don't work with all hardware, but I haven't found any hardware my no name cheapo couldn't talk to yet.

It's not that they usually don't work, but that they don't work reliably. Not a problem for a quick throw away lab setup but definitely a gotcha if used in an industrial application that should preferably have an uptime of 110% for 24/7.

What can happen is that some suddenly stop working until unplugged and replugged or possibly been reseted. One specific one has been very reproducible and it turned out to be a special byte sequence in the binary data stream that could throw its driver into nirvana.The bug is known with the manufacturer but being a low cost device they don't spend any more dollars in maintaining a released product but instead want you to buy their newest junk.

[drjdpowell]

I've heard some cheap ones don't work with all hardware, but I haven't found any hardware my no name cheapo couldn't talk to yet.

Some don’t, some do. But the ones that don’t are cheap enough to throw in the trash and get a different brand.

[Ulf]

Sometimes bluetooth is mapped as a comport as well.

[asbo]

Sometimes bluetooth is mapped as a comport as well.

As far as I know, that's only if the paired device exposes a serial interface. I haven't ever seen a literal COM-to-BT mapping, but I'd be interested to be proven wrong.

[Ulf]

As far as I know, that's only if the paired device exposes a serial interface. I haven't ever seen a literal COM-to-BT mapping, but I'd be interested to be proven wrong.

Yes, you are probably right.