unstable Ethernet connection?

[Guapo 0]

Hi to everyone! I have made an FX2N-Enet application, with remote administration, using Internet. It is working, but it is not stable enough. Some time 2 days operate fine, but after this I couldn't access it . Using ping, the connction through Internet looks like OK, but telnet Couln't establish connection with PLC. For me, it seems to lost connection between ethernet modul and PLC. Shutting down the whole system and few seconds after starting up, the connection get OK! Well, this solve the problem, however it is unacceptable! Do you have experiences like this? What to do?

[Crossbow 297]

The FX2NC-ENET-ADP is not designed for telnet connections.

[Tech Fred 3]

You need to set up a watchdog so that you can re-initialize the adapter on communicaiton loss. The primary issue is that the ethernet adapter does not allow multiple connectiosn and when you unstable etherent connection causes an abnormal loass of the TCP Socket connection the PLC does not know to release on its end. When you restart the devices this causes the listen port to be re-initialized. Fred Loveless Senior Application Engineer Kepware Technologies

[ETR Automazione srl 0]

I have tha same problem two years ago when i started a plant with 3 FX2N on ethernet with MAC 410. The problem was the lenght of CAT 5 cable over 90 m for a station. The ping request it was always OK, but the communication with PLC from the HMI it was very difficult. Now this plant have 14 FX3U Station connected in Ethernet, but each connection is not over 90 m and there are many switch to mantain the level signal good (all TCI/IP connection it's wired with CAT5 non with fiber optics). In this moment one HMI 410, two PC, one PLC and sometimes an external connection with tele service, work in the same time on the net without problem (this is not possibile with FX2 ENET ADP because accept only one channel on TCI/IP). Check the cable and the signal level. Bye

[Guapo 0]

Hi Fred! It's great! I think you are right! I suspect something similar, but I'm not specialist In Mitshubishi, even in networks. So, how can set up an WATCHDOG, and re-initialize the adapter. May I ask an sample code from you? Thans for your help! Guapo

[Guapo 0]

Yes of course, you are right! But it was the unique way to test, from a PC through the WAN, that the TCP connection does really established, or does not, with the unaccesible PLC. ..or do you have an different way for it? Please let me know! Guapo

[Guapo 0]

Hi! In my case, cable lenght doesn't play. The maximum ethernet segment doesn't exeed 30 meters. Aniway, thaks for your post! Guapo