What is the difference between a conventional RS-232 port and a RS-232 port on NI card?

[jjanssen]

I’m engineering a vacuum chamber for a part of the semiconductor process. For that I need to control a vacuum gauge and vacuum pump. The controlling and readout for those can be done with an RS232 connection. I’m gone do the programming in LabView 8.2 and I have some questions about the RS-232 hardware.

Can I use the conventional RS-232 port from the PC to do this or do I need a special RS-232 card from NI? (for example: NI PCI-8430/2)

What is the difference between those two ports?

Thanks, Jeroen

[K C]

Hallo Jeroen,  (I think your Dutch)

If your are going to use the com-port in a 'normal' way there is no real difference.

When your are going to use non-standard baudrates or want to drive long lines or ?? you shoul be carefull in your choice af hardware.

I think your application (controlling normal devices) will work fine with the com port on your PC.

(je kunt me altijd nog mailen keeswe bij zonnet)

[thehobbs]

As K C explains, the NI serial ports should behave just like a built-in COM port on a PC. 

One difference can be the amount of hardware memory buffer on the port.  I think the NI serial ports have a larger hardware memory buffer.  This once helped me with a physical buffer overflow problem I was getting on a built-in port. This is meant as an FYI; I don't think it should affect your decision at this point.