Multiple Identical Named Processor Error

[Brain Dead]

Qty 3 1756-L63 Rslogix 5563 processors
Rev 16.7


I am having loss of communication and an inability to stay on line with any of my three processors for my PAX pumps. I am able to connect at the processor locally but have severe comms drops when i try to connect over the ethernet network. It may be a long shot but the only thing I can see at this point is all three processors are named identically the same but have different I.P. addresses. Does anyone know if this would cause any type of problem? Any suggestions?

 

[iant]

can you ping them individually
what type of hub/swith are you using

 

[iant]

welcome to the site also
sorry

 

[Brain Dead]

Ping

Yes I can ping them individually, with no losses. When I browse my network through rslinx, these three processors are the only one showing multiple active connections as well as multiple lost connections.... I forgot to mention it goes through a sixnet switch into a Cisco Switch and into our CLAN whaich I believe goes through a Cisco Router...trying to discern now.

 

[allen05]

Hello people, I am new at this, so hopefully I don't make too many mistakes

 

[Ken Roach]

PING is handy for determining basic IP connectivity, but it doesn't tell you anything about the available bandwidth or any conflicts that might occur using a protocol other than ICMP.

When you say the processors are "named identically", do you mean the controller's program name, created in RSLogix 5000, or do you mean that they are using Host Names and a Host Name Server or a Host File on a computer ? Identical Host names are a showstopper in a system that uses Host Names to look up IP addresses.

When you say you can connect "locally", do you mean through the serial port, or via the Ethernet subnetwork that is local to the controller ?

I would start by looking at the local Status pages for the Ethernet module for the controller, to begin by ruling out local Ethernet media problems.

 

[Brain Dead]

No I meant the actual name of the processor....as if looking at it in Rslinx it would list he slot then the processor type then whatever the original programmer named the processor such as
00, 1756-L63 LOGIX5563, PLC_23488 where PLC_23488 is the name of the processor. All three of those names are the same and all three projects are identical, however the project names have been chande for each. I am just referring to the actual name of the processor.

 

[Ken Roach]

Having identical project names shouldn't affect communications to the controllers.

There's a seldom-used background feature in RSLinx Classic where it will create an OPC Topic automatically for each controller you go online with. Make sure that RSLinx Classic hasn't automatically created identically-named OPC Topics to each of the controllers.

My guess is that this issue has more to do with the IP infrastructure than the controllers or software, but that's just a guess. You're going to have to dig into the network and find the weak point.

 

[daba]

Having identical project names shouldn't affect communications to the controllers.

Agreed, communication to controllers, however specified, does not include the controller "name" at all, the path describes the communication "path"

Make sure that RSLinx Classic hasn't automatically created identically-named OPC Topics to each of the controllers.

I very much doubt that scenario can ever occur, ripples would have become waves by now and we would all have been engulfed long ago.

My guess is that this issue has more to do with the IP infrastructure than the controllers or software, but that's just a guess. You're going to have to dig into the network and find the weak point.

I concur, this is where you need to look