I am using an iPAQ 2215 with LabVIEW PDA module. I would like to be able to control the serial port DTR and RTS lines to provide power to an external device (<5mA needed). Is there a way in LabVIEW PDA or is there a DLL for Pocket PC 2002 that I could use?
With the LabVIEW PDA module, the only Serial VI's that you will have access to are the Serial Compatibility VI's. These VI's will allow you to read and write to a Serial Port and initialize the port, but they will not allow you to set the lines individually. You do have this capability on a Windows machine but it requires VISA, and you can not use VISA on the Pocket PC.
Hope this helps!
Regards, Steven B. Applications Engineering National Instruments
Actually, your response did not help but I did some experiments myself with the Pocket PC and I think I found a solution. By setting the Input Hardware Handshake and Input Alt Hardware Handshake Booleans to "True" in the Serial Port Init VI flow control cluster, the RTS and DTR lines will go "High." So far this has worked to power the external electronics I have attached to the serial port. Thanks for your efforts.
Excellent! I'm glad you were able to get that working. I thought you wanted to be able to directly control the state of those lines, not just power them. Regardless, I'm glad you got that working and good luck with your application. Let us know if you have any further questions.
Steven B. Applications Engineering National Instruments
this topic is quite old, so I hope there might be some changes in LV 8.20. Unlike Mr. Litwhiler I need to control the DTR and RTS Lines directly for communication with my device. Is there a possibility in LV 8.20?
LabVIEW PDA 8.2 introduced support for VISA on the PDA. You can use the VISA VI's for the PDA in the same mannor as you do on teh PC. Direct control over the lines in question is available through the VISA Property nodes.
my problem was that I needed two output and one input pin which I can control/read directly from my VI.
I'm using a FT232R from FTDI Chip (A USB - UART converter) to control an electronic device. Before that I used the COM port. When I switched to USB, I installed only a virtual COM Port, so I didn't have to change my VI. Now that I switched to a PDA I tried to use the same procedure. But when I didn't work it out I looked for other solutions and I tried another driver called D2XX driver for the FT232R. With this one I can access different pins very easily via a "Call library function node".
I didn't wrote my solution in the last reply because this solution is a quite specific one and not a general one for setting RS232 signals.