USB to Serial Adapter

[rudger]

I have a customer who wants to connect a laptop running windows XP to a CNC machine, I have spoken to the CNC machine supplier and they have advised me to use a laptop which has an on board Serial Port (either 9 pin or 25 pin) or purchase a good quality USB to Serial Port adapter as the cheap adapters will not work.
I enquired as to what products they recomend but they do not have a specific Model or brand to recommend so the question is;

What makes a good quality USB to Serial adapter a good quality adapter? and does anyone have any experience / recommendations towards which one I should purchase.

Thanks in Advance

Rudger

 

[iptech]

I did look at this for a bespoke EPOS system I rolled out last year, we used new nettop PCs and existing RS232 till drawers. In the end we did not opt to use the till drawers automatically as most purchases (low volume, high value) are made via card and the client only wanted to have one till drawer for three EPOS points per store and to automate the draw trigger would have been too complex and involved expensive software code change even though the solenoid trigger required only a single and non-specific signal.

Have a look at www.lindy.co.uk, they offer a comprehensive selection of switching interfaces, but also search for "USB to RS232 adapters" as these are used in many application envormments.

If your using the interface for machine control I would guess you'll need to implement multiple signals so look for a full-hardware adapter that can handle these easily as RS232 times out very quickly and many of the cheaper adapters rely upon software emulation which can cause comms errors and timeouts.

 

[DarDar]

Also, the full serial spec calls for a 12v signal and many of the cheap converters only provide the 5v that they get from the usb.

http://www.pccompci.com/usb-converter/usb-converter.html
http://www.adafruit.com/index.php?main_page=product_info&cPath=33&products_id=18

 

[rudger]

Thanks iptech and DarDar for clarifying what to look out for they have provided the pin outs for the connectors (attachment)



iptech thanks for suggesting Lindy I had totally forgotten about them I havent bought from them for about 10 years but always used to be very good.

Rudger