Megatron

I have a very unusual question. I am accessing my ATmel device from Lab View through USB. Its bulk in format. I am using The VISA open,Read, Close blocks properly as specified in the example provided by NI. I receive 100 packets each of 960 bytes.I a saving this in a text file. Its a simulated data, so each packet will receive only data of that particular packet number(in hex),for eg: packet 1 will receive only 1's and so on. i capture this data and i observe that packet 1 has 500 bytes of 1's and the rest 460 bytes of 2's.What exactly is happening is second packet's data is getting overwritten in the first packet's data. The board is sending data every 20 ms. I crossed checked it in hyper terminal i saw that my device is sending all values properly.So from firmware side there is no issue. I am not doing any sort of processing in between. I directly capture the data received from the board. The timeout given in VISA Open is 2000 ms and the byte count given for VISA read is 5000. Is it a timing issue or anything else?

Hi, I have to interface Lab View with a CIF 50 Hilscher Profibus. I read through some of the documents provided by Hilscher, it talked about Sys Con, OPC servers etc etc. Through this profibus i have to control a valve box through RS-485 communication. The first task is basic read/write.Through lab View i have to read the number of bits through CIF 50 bus in turn to the Valve box. Can anyone tell me where should i begin?