LINDY Technical Support Forum

Hi all,

We are using USB to 4 Port RS-232 Serial Converter, 4x DB9 Male (Part No. 42858)

Port numbers in Device manager sometimes appears not in order. We can simply change the port number but still we need to find corresponding serial ports in the converter as it connects like

Communications Port (COM14) -> Second port in the converter
Communications Port (COM12) -> Third port in the converter
Communications Port (COM13) -> First port in the converter
Communications Port (COM11) -> Fourth port in the converter
It sometimes makes setup or specially remote support difficult as we cannot see physical connection of four barcode scanners.

We want to setup the converter as follows. (basically port in order with consecutive port number with the same port order in the converter)

Communications Port (COM11) -> First port in the converter
Communications Port (COM12) -> Second port in the converter
Communications Port (COM13) -> Third port in the converter
Communications Port (COM14) -> Fourth port in the converter

and we found that the port numbers are changed sometimes even when connected devices are in use. For example, scanner 3 is scanning for sales 3 and suddenly it is changed for sales 4. then we found port number 3 and 4 is swapped over. Could this be happend?

I would appreciate if you can advise how to set the converter properly.

Thanks.

Hi Posnet,

It sounds as though the converter or your connected devices are re-handshaking with your computer which is causing different COM ports to be assigned.

I'm afraid there isn't really a solution to this with this product, you would need a converter that supported COM Port Retention. Unfortunately this does not currently.

The only adapter we currently stock that supports this is a single port version:
https://www.lindy.co.uk/usb-firewire-c4 ... n-1m-p8355

Sorry I can't be of more help on this occasion.

Guy

Hi,

Thanks so much for your reply.

It is a big help to let us know that the product 42858 does not support COM Port Retention.

I'm not being sarcastic. It is really good to know what a product can do or can not do.

Otherwise we have to spend a lot of time to find it out, if there is no definite answer from the manufacture which usually happens with generic products and that is why we choose Lindy. great products with great supports!

Anyway, I'm just wondering if COM Port Retention is hardware or software(driver etc) side

We also use many USB to Serial Converter Lite - 4 Port (42690) and does the same thing.

Thanks in advance.

Hi,

No problem, we always try to answer any questions asked of us.

I'm afraid COM Retention must be built into the chipset, and enabled in the software. If the chipset does not support it, then it is not possible.

Let me know if you have any other questions and I'll be happy to help.

Guy