PDA connect to PLC

[Zoyo]

Hello,

I made a small application to my Acer N311 PDA by LabVIEW PDA 8.2 and the application should communicate with a PLC (brand: Moeller). My PDA has a syncron cable wich is IRCOMM --> USB. The PLC has a Serial cable with female plug.
My question is: how can I connect to this two ends? So the USB and a female Serial. I know there is plenty of solution for this kind connection like USB to serial cable, but the thing what is not so clear for me, I have to connect that 3rd cable and that's all? or I have to configure something on my application like RxD or TxD?? because the USB has only 4 pin and the serial has 9.

Thanks in advice.

B.R.
Z

[Zoyo]

So my question is I have to use a nullmodem cable so the RD and the TD have to be crossed or simply and soleny I have to connect this 3 cable and everything is working automaticle?

[Kumaran]

First of all you cannot use RS232 to USB controller to connect your PDA to PLC. to my knowledge there is no RS232 to USB converter with PDA support. You may have to check the ACER website for the cradle with RS232 connector cable. If your PDA has got serial communication support, then generally manufacturer will have a cable with RS232 connector. 

Then you can try null modem mehtod for serial communication checking.