LabVIEW TCP IP with ENC28J60

[MohamedYaqoob]

Hi,

I send simple TCP/IP messages from the ENC28J60 and receive them in LabVIEW. sometimes It works ok, but It does not most of the time.

My problem is this:

After sending and replying to ARP requests to interchange the MAC addresses, I send a [SYN] flag from the ENC28J60 and I can see that it goes to the PC and it is correct from observing the packet with WireShark. But LabVIEW only sometimes reply back with [SYN, ACK]  and then receive my message correctly. But most of the time it does not reply with the SYN flag; it just reply with the [ACK] flag which is not what I expect.

1. This shows when it works:

2. This is when it does not work

WireShark shows that the packets I send from the ENC28J60 are all correct and free of errors. I don't understand why LabVIEW does not reply with [SYN, ACK] most of the time (i.e. it does for few times).

Thanks,