Re: serial port interfaced EEPROM reader no longer detected after temporary removal

But the craziest thing is that nowhere do I see COM2 except in the rename option for COM1. And, when I try to remove COM1, what happens is this: device manager tells me to reboot the machine, I do, and when I come back up for air there is COM1 in the device manager, working correctly as if I never did anything. No found new hardware dialog either. It's as if it was never deleted. My only other option, to say No after it asks me if I want to reboot, seems not to do anything.

Bob I wrote:
Interesting. I wonder if the original instance of COM1 got set to be COM2? Remove both COM1 and COM2, and then restart. You should come up with a single working COM1 after new hardware found is done. This is a frequent occurrence/problem with USB/Serial ports.

Margo Guda wrote:



Bob I wrote:

Serial ports were not designed to be hot plugged, but people "generally" get away with it. What port is the software looking at for the reader? Does the system claim that the COM1 is in use?

The software is looking for COM1. I opened its properties *** in device manager, and it shows working correctly as the status. In the advanced options I looked at the possibility to rename the port, and noticed that COM2 has (in use) behind it, but as far as I know I don't have COM2 on my system.
The manufacturer of the EEPROM reader tells me that the software scans for available serial ports (1 through 4) and you can set one that is available. I've tried that on another computer (not my own) and it worked. But in this case I cannot get it to work.
I also tried using a serial-to-usb converter, but so far no luck: I borrowed one, that is supposed to come without drivers, and windows tried to find a driver for it and failed. It went on the net to look for a driver and says it cannot find a driver. The person who lent me the plug says it did not come with a driver. Any ideas?


Margo Guda wrote:

Can the serial port be damaged by hotplugging?
What I did was this: the reader has a pluggable cable that goes into a telephone-style connector on its side, and a ninepin RS232 on the other. I unplugged the reader end.
I have since tried to uninstall the port (does not work; I have to reboot the machine and when it does, the com1 is right back where it was), powered down the reader (it has its own power supply) and rebooted the computer various ways, with the reader off (its normal state) and with the reader on. None of those makes any difference. It will not interface with the computer. And I don't have anything else to test the port with. The device manager says it's working correctly.


Bob I wrote:

Hopefully, you didn't damage it "hotplugging" it. Perhap going through a uninstall, reinstall will get it recognized again. It may be that the COM2 was assigned because COM1 was in use.

Margo Guda wrote:

Yes. It did not help.

Bob I wrote:

Just a thought, but did you restart the computer with the device attached?

Margo Guda wrote:

I have an EEPROM reader that connects through a serial port, of which (according to device manager) I have only one on my xp pro sp2 system. This is supposedly COM1.
I had to remove this reader for a few minutes (to test on another computer), which I did; when I put it back on its original system, the software used for getting data off it no longer recognizes it.
I checked the device manager for the port it connects to, it is COM1 which shows as the only serial port (other than the plethora of USB ports available), but when I look at port settings, I see something under COM2 as in use. I am not aware of anything that could be using COM2, which does not show up on the device manager. I don't have a phone modem anymore, so what can be happening?
Can anybody tell me how to make my device visible to its data reader again? Help would be much appreciated.

Margo Guda.







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