Siemens CP343 Profinet help

[Blue Fox]

Hi,

I have a customer with a S7300 from around 2013 which they link to approx 25 inverters, 3 DP to DP converters and 5 IM153 remote I/O units all on a Profibus network. They are now looking to upgrade initially the inverter comms then next year the rest to Profinet. This initial push on the inverters is due to the exisiting Profibus cards for the inverters becoming obsolete. The site uses a CP343 unit to connect to a SCADA server. I am thinking I can use this unit as a Profinet connection to the inverters? It has 2 ports, one of which is currently un used. Anyone used a CP343 unit to do this before? I'm looking to connect directly from the CP343 to a single inverter initially whilst I sort out the comms and get it all up and running, then down the line connect the CP343 to an unmanaged switch and use that to connect to the inverters and the other I/O units in the system. The inverters Profinet cards have 2 ports so work as a switch to allow an in/out so I can connect all the inverters in a daisy chain.
Any advice on doing this would be very gratefully received, I've used profinet on the S7 1500's and S7 1200's before but not on an older S7 300.

 

[JRW]

Heres my take

I would replace the older 300 cpu with a 31x-2 DP/PN version. Then put the new profinet drives on the PN port of the cpu.

Doing it this way the DP network can stay there and you can slowly move the DP devices to the PN port too



on another note

The CP343 (only certain ones are profinet I/O controllers) uses certain send and receive blocks for IO control.
Chances are your drive blocks will have to be rewritten when using a CP343


This has been my experience... Lets see what others folk opinions are

 

[mk42]

There are at least 3 models of CP343, make sure the one they have supports being a profinet controller.

If the 300 has an integrated PN interface, PN works well. If not, then you have run some instructions to read/write the IO to/from the CP on top of whatever else you'd normally do. It isn't an insurmountable level of work, but copying data from the CPU to the separate memory in the CP is an extra layer where things can go wrong (I think the CP even has it's own run/stop?). Also, the S7-300 backplane is way slower than an ethernet cable, so that can be a surprise bottleneck.

The steps of setting up a PN network are the same for 300 vs 1500. Assign the device names, DL PLC program, everything should start talking if it all matches up.

 

[mk42]

Heres my take

I would replace the older 300 cpu with a 31x-2 DP/PN version. Then put the new profinet drives on the PN port of the cpu.

Doing it this way the DP network can stay there and you can slowly move the DP devices to the PN port too

Agree. Getting a PN CPU will really simplify things, and might be required if servos are involved.

 

[AlfredoQuintero]

Hi. I agree with the recommendation from JRW and mk42.
I have one CP343 and it is a very special PROFINET master, from the early days when the specification was being developed. I only use it for programming interface. Many PROFINET IO devices do not work properly with it or require a lot of work.

One other possibility would be to use a Hilscher product with is PROFIBUS slave and PROFINET IO master. With this solution your S7-300 will see another PROFIBUS DP slave and the 50-DP-EN will handle the PROFINET IO communication. This may be cheaper than getting an 31x-2 DP/PN.
Good luck with your endeavor.
Hilscher's NT 50-DP-EN

 

[L D[AR2P#0.0]]

S7-300 is on the discontinued path so using a CPU 3xx DP/PN version is not an upgrade - migrate to an S7-1500 based system.

 

[mk42]

S7-300 is on the discontinued path so using a CPU 3xx DP/PN version is not an upgrade - migrate to an S7-1500 based system.

It's a fair point.

From my perspective, moving to a PN 300 saves the engineering cost of migrating the project to 1500 & Portal, and is a good middle ground between running the IO off a new CP and doing a full migration. But it doesn't fix any product lifecycle issues, this is true.

 

[JesperMP]

I also join the pack that recommends to upgrade to a 31x-2PN/DP; it is straightforward, and you can transition from DP to PN in steps.
Keep the CP343 for the SCADA connection.
I also agree that migrating to S7-1500 should be considered. But it will take significantly more effort, and it will mean that the SCADA has to be updated as well (the connection and process tags will change).

edit: I think the expected lifetime of the plant must be deciding if you go for a solution based on S7-300 or S7-1500.
Anything more than 5 years, then go for the S7-1500.

 

[JERA]

There is two ways to make the upgrade:
1) Upgrade with a 31x-2PN/DP - no trouble but remember the limited lifespan of s7-300 and the speed between CPU and CP card is only 187.5 kBd due to the backbone bus.
2) Upgrade to a S7-1500 CPU with 2 ports and use IE/PB link (PN IO gateway between Industrial Ethernet and PROFIBUS) ordre no. 6GK1411-5AB10

I have made solution 2 for a client and the conversion went smooth. We have now the system on the S7-1500 CPU platform (CPU 1516) with no IO card change and rewiring of IO, due to the IO card of the CPU was and remote I/O racks was put on ET 200M IM 153-4 PN, so it was om Profinet.

The DP to DP converters can also be changed to IE/PB link, so your side is Profinet and the other side on Profibus as now.