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.

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?

Thanks in advice.

B.R.

Z

[Yair]

I believe the port on the PDA is a standard serial port, which you can address from your LabVIEW program. Usually, only 2 or 3 of the pins in a serial connector are used and the documentation for the PLC should reveal which ones (I believe it's 2,3 and 5 in your case, but you should make sure).

I'm not sure, but you might not be able to find the same documentation for the PDA connector, since they're probably proprietary. That said, you can try searching or finding it out yourself by hooking it to a PC and checking one pin at a time.

Once you have that, I believe that making a direct connection should simple. Personally, I usually prefer using a TCP to serial converter and then connecting through a Wi-Fi access point. Costs more, but saves you the trouble of having to set up cables.

Incidentally, how are you planning on talking to the PLC? I tried talking to a Moeller PLC a few months back and it took me a long time before I found partial documentation. I wouldn't mind more information if you happen to have it.

[Rolf Kalbermatter]

QUOTE (Zoyo @ Jun 23 2008, 05:29 PM)

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.

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?

Thanks in advice.

B.R.

Z

In addition to what Yen said you will not use the IRCOMM->USB cable at all. That USB interface is a real USB device interface that needs a USB host controller to interface to and that probably gets installed in your PC as a virtuel COM port. The software that makes this USB interface look like a serial port to your PC program is a driver on your PC. There is no way to directly connect that USB cable to an RS-232 port.

That said your IRCOMM port is in fact most probably a serial port but as its name would indicate most probably an infrared one. So you would need to find an IRCOMM to RS-232 adapter for your device. Then you might need to figure out the pin 2 and 3 configuration as is common for serial comm and after that the real fun starts by implementing the Moeller serial communication protocol, which according to Yen there is little documentation for. Since the PDA is not x86 based an existing DLL to communicate with the PLC will not help as you can't run it on the PDA. So implementing the protocol on your own using the serial port functions on the PDA is the only solution.

http://pinouts.ru/PDA/acer_n30_pinout.shtml' rel='nofollow' target="_blank">Here is the pinout of the connector but I couldn't quickly find a manufacturer of a cable that provides the RS-232 part of this proprietary connector on an DSUB-9 connector.

Rolf Kalbermatter