RS-422 support


#1

Does the Plugable USB to RS-232 DB9 Serial Adapter (Prolific PL2303HX Chipset) support RS422?


#2

Hi RJ,

Thanks for posting your question here, I’ll be happy to assist. The product information page for the PL2303 chip that’s in our USB to Serial cable does list RS-422 support.

Here’s the link:
http://www.prolific.com.tw/US/ShowPro…

I haven’t tested it myself though, so I am unfamiliar with it’s implementation but we’ll do our best to help if you have any troubles.

Thanks for asking,
Jerome.

Plugable Technologies


#3

I noticed in the data sheet that several pins need to be driven externally to 5V. My main question is… are those pins driven high internally from the USB or do I need to do that on DB9 side?


#4

Hi RJ,

According to the product overview available here: http://www.prolific.com.tw/ShowProduc…

The PL2303 provides flexible signal level requirement on the RS-232 serial port side also allows the PL-2303HX to connect directly to 3.3V ~ 1.8V devices.

Hope this helps.
Thanks,

Jerome.

Plugable Technologies


#5

Late reply on this, as I came across this thread while searching for information on using this adapter to connect to a device with 3.3v signal levels.

While the PL-2303HX chip used in this adapter WILL work with 3.3v signals, there is also a SP213EEA chip (manufactured by Sipex) that converts the TTL voltage levels from the 2303 to 12v levels, -12v-12v was the listed range on this chip, but without further checking of the circuit I can’t verify that it uses this full range.

Short story, attempting to use this serial adapter with a 3.3v level connection will not work, it will only receive/transmit garbage data at best.


#6