September-13th-2020, 10:56 PM
Hi there!!!
I am coming whit an idea that I dont know if is posible and I would like the opinion of some of you.
I am 5 machine, 2 with cp343 and the other ones without Ethernet port. All the PLC are S7 317.
The thing is that we dont hace access to the plc proyect of the 2 plc that have cp343 to change the IP the configuration hardware. (I know all the variable address...)
So, I was thinking install 5 x NL 50-Mpi and read with node Red, more or less 100 variables of each one and the send to mysql for example each 1 or 2 minutes...
I would like to use node Red to reduce costs from licenses a Opc server...
What do you think, Is possible? Any other recomendation? What about the performance?
Many Thanks!
September-14th-2020, 05:16 AM
Hi there,
first of all a word to the NL 50-MPI. This device works nearly with a zero delay. So once a command is coming via Ethernet port it is instantly sent out on MPI side. But there are differences in the performances of the S7 PLCs on MPI. Some S7 PLCs of older types are responding on a request in 25msec ... newer ones in 1-2msec. If you have luck you have a new PLC and you are getting good response times.
To use Node-RED with NL 50-MPI you need MPI nodes. There are two offerings:
a.
https://flows.nodered.org/node/node-red-contrib-s7comm
b.
https://flows.nodered.org/node/node-red-contrib-s7
I don't know the advantages of each to them. So you have to give it a try yourself which one is better.
You say that you have to read 100 variables ... I can recommend to you if it is possible to read adjacent variables that are lying next to each other in one command. So not 20 times DBB 0, 1, ... 19 and so on but DB 100 of a length of 20 bytes in one shot instead. Then you can divide them in Node-RED faster than 20 separate reads would cost you time.
I know Node-RED includes also a mysql node. I have never use it. You have to read the documentation about how it works.
What I did not understand is the fact what you want to do with all the data after it was written to the mysql database. I have read "saving money" on licenses for an OPC server ... I think you mean OPC UA server not OPC server, right? So I know there are also OPC UA server nodes available in Node-RED. Overall I think nobody can give you a guarantee about the performance. I personally see no problem in using 5 NL 50-MPI devices with Node-RED to read data in 1-2 minutes from 5 PLCs. I hope the S7 Node-RED nodes support multiple IP addresses for multiple NL 50-MPI cause I don't know.
Good luck with your project.
„You never fail until you stop trying.“, Albert Einstein (1879 - 1955)
September-14th-2020, 01:56 PM
Yes. NL 50-MPI is just a converter from TCP/IP to MPI network. So NL can work on Ethernet side at any IP address you assign it to.
The NL 50-MPI has an embedded web server where you can edit the IP-Adress or you can configured it with the Windows Tool. Both methods will lead to the same result. Here is the latest toolsuite for Windows for it
https://download.ibhsoftec.com/neutral/I...7Setup.exe.
Thx
Armin
„You never fail until you stop trying.“, Albert Einstein (1879 - 1955)
September-14th-2020, 01:59 PM
And also NL 50-MPI is 100% working the same as CP343. Siemens STEP 7 or TIA see no difference and "thinks" on Ethernet side it is original CP343.
But this forum is not giving any support for NL 50-MPI. I just can highlight was I know from this product.
„You never fail until you stop trying.“, Albert Einstein (1879 - 1955)