Have a remote lift station that uses an Ethernet connection to talk to the building right next to it, and from there it communicates via radio to the main plc at the wastewater plant. Im new to the position, and from the very start I replaced the ehternet hub, and that stopped the failures, for a month. Now they are back and im perplexed. any help would be great.
keep getting ethernet failure alarm
- Thread starter fgoodsky
- Start date
Ken Roach
Lifetime Supporting Member + Moderator
Welcome to the PLCTalk forum community !
Please provide as much context and detail as you can.
What form does the "ethernet failure alarm" take ? Do you know precisely what it detects ? Where was the "ethernet hub" (an obsolete sort of device) that you replaced located in the architecture ?
What kind of radios are used ? How far does the radio signal travel ?
This could be a PLC problem, and Ethernet infrastructure problem, a radio problem, a SCADA alarming problem.... it's going to take some work to narrow it down.
Please provide as much context and detail as you can.
What form does the "ethernet failure alarm" take ? Do you know precisely what it detects ? Where was the "ethernet hub" (an obsolete sort of device) that you replaced located in the architecture ?
What kind of radios are used ? How far does the radio signal travel ?
This could be a PLC problem, and Ethernet infrastructure problem, a radio problem, a SCADA alarming problem.... it's going to take some work to narrow it down.
an odor control building within the sewer system talks with a sanitary lift system right next to it that monitors the level of and controls motors that send sewage to the wastewater plant. the lift system talks via a 4rf radio system that never fails. the lift system and the odor control building are connected via ethernet port, and all we get is an ethernet failure. i replaced the ethernet switch and it fixed the problem for 1 month, now im getting ethernet failure, that clear up on its own after 10-60 mins.
Ken Roach
Lifetime Supporting Member + Moderator
What exact form does the "ethernet failure" alarm take ? Is it a SCADA tag ? An autodialer alert ? Something that fails to update that you infer a communications failure from ?
James Mcquade
Member
how long is the ethernet cable? 100 meters / 330 ft is max, but i would not go past 275 ft. the ethernet cable may be bad, the ends may be bad and need to be redone.
you might consider fiber optic cable and use ethernet converters on each end. if you go fiber, use multimode.
james
you might consider fiber optic cable and use ethernet converters on each end. if you go fiber, use multimode.
james
its no longer then 50 feet. was getting failure almost 1/day, then i replaced the ethernet switch and it didnt fail for almost a month.
AlfredoQuintero
Lifetime Supporting Member
This sounds more like a physical, rather than software or settings issue. Is this cable routed in parallel or close proximity to AC lines, or close to illumination equipment which may be inducing noise? Is the switch you are using a managed switch? If it is, I would advice to see if the switch provides diagnostics information such as error counters which seem to be increasing.
James Mcquade
Member
Maxkling,
the longer the distance, the more you increase the possibility of packet loss.
Multimode fiber gives a better thru put in regards to communications between systems than single mode fiber.
james
the longer the distance, the more you increase the possibility of packet loss.
Multimode fiber gives a better thru put in regards to communications between systems than single mode fiber.
james
The fiber portion of this is incorrect for anything up to 10 gigabit(it gets a bit hazier here as the 'specs' beyond this point don't talk to singlemode specifically anymore).
Both multimode(if using OM3,4,5) and singlemode fiber support 10 Gigabit speeds using the proper transceivers.
Single mode just supports that same speed up to 10km, where OM5 is going to top out ~400Meters.
It is a communication failure for sure. I dont mean the ethernet connection.
4rf radio system.
50 feet.
Replaced the ethernet switch.
The error came back after a month.
You get the error once a day.
That is what you have told us until now.
Exactly what are all the devices used in the system Name and Type no ?
Exactly what software is used, Name and type no ?
How does the error manifest itself ? In some software as an error code ? If so what is the software and the error code ?
Does the error disappear by itself ? Do you do something to clear the error ?
And what is your role in this ? Did you design the system ? Did someone else ? If so, what does that someone say about the errors ?
4rf radio system.
50 feet.
Replaced the ethernet switch.
The error came back after a month.
You get the error once a day.
That is what you have told us until now.
Exactly what are all the devices used in the system Name and Type no ?
Exactly what software is used, Name and type no ?
How does the error manifest itself ? In some software as an error code ? If so what is the software and the error code ?
Does the error disappear by itself ? Do you do something to clear the error ?
And what is your role in this ? Did you design the system ? Did someone else ? If so, what does that someone say about the errors ?
James Mcquade
Member
Dravik,
in regards to the fiber optic cable, i am going on what i was told from a coworker who has been setting up all our 33 plant networks and my experience with single mode fiber at another plant.
james
in regards to the fiber optic cable, i am going on what i was told from a coworker who has been setting up all our 33 plant networks and my experience with single mode fiber at another plant.
james
Ahh gotcha, Yeah there's a lot of reasons TO use multimode, especially in internal plant networks, cost tends to be more reasonable for the transceivers for example. So if you have a pile of spare SFPs that are rated for multimode for example, or some of the industrial switches that have native fiber ports that only support MM, makes total sense.
But I deploy a lot of both and speed isn't a selling point over SM, yet...
We certify Ethernet to 100 meters, if you are having problems with packet loss or error at less than 100 meters you have other issues. We have some runs, especially for cameras that go beyond 100 meters, just depends on use and devices and what speeds you need. We tend to use multimode just in racks and short runs because of the speed restrictions over distance, the cost is less. Trunks and backbones are almost always single mode because of the greater speed at distance.
Either way we are getting side tracked because it seems none of this is helpful to the OPs problem, ha.
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