network architecture

mobil1syn

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Dec 2018
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im trying to accommodate the customer request and need a sanity check of sorts.

using a redundant controllogix controller, prosoft modbuss and customer is asking for the following redundant modbus communication. i would like to keep the controllogix chassis to 4 slot. if i use the prosoft gate way i need 8 of them and two switches, creating a primary ring and secondary ring.

the other option i think might work but am not sure since my experience with a system this large is limited, can make a ring with the chassis modules? do they have dual copper ports? i am having a hard time finding information if this is possible.

ARCH.jpg
 
You can't put Prosoft modules in redundancy chassis, they must be in I/O chassis.
Your system will not sync.

Also make sure that all switches in DLRs are actually supporting DLR in hardware - I cant read cat number on you picture.
 
You can't put Prosoft modules in redundancy chassis, they must be in I/O chassis.
Your system will not sync.

Also make sure that all switches in DLRs are actually supporting DLR in hardware - I cant read cat number on you picture.
good to know about them not being able to get into the redundancy chassis.

i did have this epiphany last night on my mtb ride that will be relatively cheap and simple to implement.

ARCH-2.jpg
 
I think what you have sketched out will work.

You don't show power for the ETAPs, Gateways and Ethernet Modbus Switches. In my experience, the power supplies fail more often than any controller does.

For your 24V, the 1606-XL series power supplies are rated for N+1 redundancy ... so if you need one, you can wire 2 in parallel and if one fails, you are good. See technote 28188 for the full info on configuration

If you have any 120V powered equipment the options are not that great :(

There are a couple of (non-Rockwell) power-bar type switching supplies that select from 2 incoming 120V power feeds
 
its odd, most of the time the customers are concerned with processors having redundancy but not other items. in this case the skid mounted I/O is all flex I/O and they havent said anything about that not being redundant. getting information for this project has been a challenge and they have been constantly changing their minds.

i do my best to keep everything 24vdc powered. about half out customers are outside the US so dealing with varying voltages and hz is a giant pain. i have a unit here that is single leg 220v 50hz that we needed to run. ended up having to switching a handful of relays, solenoids to do our testing since yea getting that power just isnt going happen.
 
Second drawing is better but still has illegal loop - Stratix 2000 does not support DLR.
All devices within DLR must have hardware that is DLR enabled. Should use 10 port Stratix 5700 instead. And even with that, not all 5700 support DLR.
 
Second drawing is better but still has illegal loop - Stratix 2000 does not support DLR.
All devices within DLR must have hardware that is DLR enabled. Should use 10 port Stratix 5700 instead. And even with that, not all 5700 support DLR.
forgive my ignorance as i am still learning how the networking side of things work. are you referring to the fiber switch or the switch on the modbus side?
 
One labeled NTP and HART.

Also ETAP with two copper ports cat number is 1783-ETAP - you have it as 1783-ETAP2

Capture.JPG
 
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What about hanging HMI from a Stratix Switch connected to ENTR2 on Both Racks and then using a DLR for the IO and the Modbus gateways on ETAPS. The NTP and Hart Protocol then come into the Stratix8000 on Entr2 with the DLR ring is handled by ENTR1 on both sides. If your scared the Stratix will fail Double up with a single cable between. Redundancy networks are not hard if planned correctly. What is above in the original comment #1 mobil1syn by and the comment #3 by "Mobilsyn" are way to complex and won;t work #1 because you have a porsoft card in the main racks beside a redundncay card in #3 does the Screen support DLR networking?
 
I have to came to the conclusion that most redundant setup add more risk than reducing it.

I agree .. mostly.

Redundant switches have enabled our IT guys to update switches while we are on the run (or at minimal production on a maintenance day) without losing our process. As long as they don't update both switches in the same cabinet during the same 15 minute span.

Redundant (24V) power supplies have saved us from a few power supply failures ... maybe 5 of them in 18 years. The 24V powers up instruments, fieldbus, non-cisco switches.

Redundant Controlnet CNBR and CN2R and dual 1786-RPFRL WOULD HAVE saved us from 3 or 4 1786-RPFRL problems in 18 years. We have begun to change out the CN2 and CNB, add the seconds set of RPFRL on the additional fiber pairs between MCC rooms and Load centers. This was a known issue during our control system design in 2003 and no one mentioned it during the architecture reviews (SIGH). So I wish we had these in place to begin with.

The complexity of the redundant ethernet switches ... maybe it was worth the convenience, maybe not.

The rest has paid for itself.

No redundancy on controllers, inputs, outputs, etc. It's bad enough to keep one set of field I/O running. The programming and alarming get NASTY when you have 2 sets of inputs and they don't agree. If you believe the worst case (safest) then you just have double the chance of failure. If you believe the best case (better uptime) you still need to alarm so that it gets fixed ... that has to wait until the machine is down for maintenance anyway. Then you have the naming problems with 2 different inputs monitoring 2 different switches that measure the same thing ... ick!o_O
 

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