S7 communication with node-red

bergmanu

This Application Example shows how to use the SIMATIC IOT2000 to communicate with an S7-1500 PLC via S7 communication

 I have done all the steps mentioned in this document and am able to deploy without error.  But if I change values in S7 1200 cpu , nothing happens in node-red.   

With no error message where can I start de-bugging

I would to read a Date_and_Time variable from PLC with the S7 Node installed on Node-Red, but I can't find the right address for the parametrization of this variable in Node-red.

my variabile is DB5,TOD8

I've tried:

DB5,TD8

DB5,DT8

DB5,DATE8

DB5,DAT8

DB5,DTL8

but any of these doesn't work.

Do you have a list of address types based on variable types from S7-PLC?

Thank you

 Thank you bergmanu!

I tried also with DTL but I cannot read the whole variable using the same address posted in my first topic.

In this case I have to read the variable as an Array splitted in the USInt element Year,Month,....etc ?

Best Regards

bergmanu

Hi davide_maffei,

with Date_And_Time it is not that easy, because it uses the BCD format.

If possible use DTL instead, it is more easy. Is it possible for you?

Here is some documentation but not really a list: https://github.com/plcpeople/nodeS7/blob/master/README.md

I am testing it with Date_And_Time at the moment. Since now I only had success with DTL.

Best regards!

Hi, I have S7-1500 (no optimized DB) and a flow with s7-in node of node-red-contrib-s7 that worked on v 0.14 of Node Red, but now I upgraded Node-Red from the default version 0.14 to the 0.16.2 using the command

npm -g -unsafe-perm node-red

and now the same flow give me the error

"Error connecting to PLC: Error: read ECONNRESET"

and I cannot read anymore from the same PLC the tags.

Do you know if with this version the S7 node is not supported anymore?

I have to use the iot2040 for a demo to customer next week, so I have to fix this error. Can you give me some help?

Thank you

Hey,

I think it's possible that there is no support for the 0.16.2 version of node-red, because the latest s7-node version was before the new node-red version.

I have also a question:

Where is the limit of values to read from a s7 plc? How many values per read process are possible?
Are there some informations about it?

Best regards
Sebastan