Multicast problem with Rockwell Automation Logix

Deal all
I am try to survey a industry switch for my factory. My factory use Rockwell Automation Logix PLC and 1756-ENBT module, the other side use 1794-AENT FLEX I/O module, I have enable the IGMP Snooping and Query functions of switch, But still can't establish the I/O connection. I have searched this forum and I found someone say that some PLC use unnormal multicast I/O connection. So can someone tell me what I meet is Multicast problem of PLC or just compatable problem of switch??
Thanks

Have you set up the IP addresses of the ENBT and AENT?
Are they on the same sub-net?

Yes, I am very sure that both PLC and Ethernet I/O module are as the same network submask.

Thanks you ^_^

Kid, you wouldn't believe how many people post to this Forum with Ethernet connectivity problems who don't know how to PING.

I presume you've connected an unmanaged switch or hub between these two devices to prove that the Logix and AENT configurations are OK, so let's hear what the Connection tab for the AENT module says that the connection error code is.

More information is always handy.

What brand and model of swtich are you using ?

First like Ken said, PING both modules.

If PING to both devices works, your I/O control should work.
If ping does not work - you have to get someone on-site who knows Ethernet a little better than you are or switch to a different network your know litle more.

Few things to check:
- for start disable IGMP snooping and any kind of virtual neworking on your switch.
- make sure ENBT and AENT are not a part of the company network.
- make sure both devices are not separated by a router - multicast will not go through a router.
- check for exact error code you are getting in RSL5K - it will give you some idea

Ab- I/O control uses multicast - this is a normal transmission via Ethernet if set correctly.

I also vote to use ping. Use the Rockwell Utility BOOTP/DHCP Server to set the IP address if ping does not work.

If the IP address are ok, check the RPI. The default is pretty fast, I think 5 ms. It can be set as low as 1 ms. Start high like 100-200 ms and lower if your application reqires it. My switch (N-Tron 508TXA) lockes up with too much traffic. Without IGMP snooping the switch would lock-up very easily.

Sam

Samneggs said:

IMy switch (N-Tron 508TXA) lockes up with too much traffic. Without IGMP snooping the switch would lock-up very easily.

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That is strange, may be you have an older switch. I am using N-tron 509FX on my test bed and it can handle easily 10,000 packet/sec per port.

I have heard that there was a bad batch of N-Tron switches shipped shortly after they revised the firmware to include port VLAN.

Derek McFarland said:

I have heard that there was a bad batch of N-Tron switches shipped shortly after they revised the firmware to include port VLAN.

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That sounds familiar, I just don't remember details