convert RS485 PCI card to RS232

[jjs49]

We have a National Instruments 184686C-02 PCI card (it may be around 12 yrs old). It is operating as RS485 2 channel. Etched on the PCB is "PCI-232/485.2CH". That leads me to belive that the board could be populated for either RS232 or RS485 operation. Is there a way to change the location some of the 0 ohm resistors to switch from RS485 to RS232 operation?

Thanks for your help!

[Drew_H · Accepted solution]

Hi jjs49,

Unfortunately that naming convention does not mean that the board is capable of both modes of serial communication.  I believe it was put there because the same PCB was used as the base for both the RS232 and RS485 versions of the PCI card, but each device has different power requirements, as well as different data line protection and maximum transfer speeds.

I believe this misconception came up a couple of times back when the card was still supported, as I found quite a few references to the below KB in past issues.

Is My Serial Board a RS-232 or RS-485 Serial Board?

http://digital.ni.com/public.nsf/allkb/7C785C3AD15CF2DA86256CC2006A5D3C?OpenDocument

[Vkumar]

If you have data sheet of board 184686C-02, could you please provide me.

I would like to use this board and need DB-9 pin diagram.

Thanks