Annoying problem with TCP/IP programming

Ad_My_Xperience

Hello guys,

there's something strange with my TCP/IP programming to read a file from a web site (RSS file for weather).

I have 2 NI-3100 controller and I load same program in both. The first one reads file but the second doesn't. Both have internet access (I also have traffic cams images).

I don't know if it's related but I also use TimeManager to execute code on sunset and sunrise event. (I know TimeManager is discontinued so I want to replace it with Astro_Clock).

With the second controller who doesn't read file I try to debug step by step to try to see why controller doesn't read the file but in DEFINE_PROGRAM section I have 'WAIT 1' insctruction and I receive an error message about wrong path for i!-TimeManager.axi or i!-TimeManager.axs file...

ericmedley

Assuming the code is exactly the same in both masters the problem must be somewhere with the network. Have you tried swapping the IP addresses of both masters and seeing if the problem follows the IP address? Also, are both masters one the exact same switch or are they in different parts of the network? It is possible to have a problem with the NIC on the master but since you are able to connect to it otherwise, I wouldn't think this was the issue.

MLaletas

If the processors are static'd do you have the dns settings the same on both?

Ad_My_Xperience

Both controllers have same fixed IP, same cable, same switch, same firware. I install first, no problem, I remove, install the second and no connection with ip_client_open command.

I've activated Netlinx Internal Diagnostics Messages and I see : UNKNOWN HOST: with the name of the web page I try to open

It's very strange, ASTRO_CLOCK command doesn't run

ericmedley

Ad_My_Xperience wrote: »

Both controllers have same fixed IP...

Same IP address??? that's not right. They should have their own unique IP address. Otherwise you have a conflict.

pdabrowski

ericmedley wrote: »

Same IP address??? that's not right. They should have their own unique IP address. Otherwise you have a conflict.

He did say that they were swapped out so the same IP would not be on the system at the same time.

HOWEVER..... You're probably a victim of a router/switch/other device like the DNS server that is not updating its ARP table quick enough to reflect the change in physical hardware that the IP address belongs to... This can be a thing from time to time on older Cisco hardware!!!!