Hello

for multiple S7 1200 cpus what do u think best configuration for the network ?

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Split from How to increase maximum modules of S7-1200.

My network will be at first 2 S7-1200 cpus the second cpu used as extension for I/O number,and one HMI.

then in the future will add another 2 s7-1200.

Hello Engea;

Profinet would appear to be the easiest way to setup your network, all S7-1200 CPUs have an integrated PN interface and can be used both as IO controllers and I-Devices, as extensions of the controller IOs..

I would suggest you start working with the following link:

Configuration and Application of the PROFINET I-Device Function

https://support.industry.siemens.com/cs/ww/en/view/109478798

Study especially the linked document:  "I-device in a standard environment"; the IO controller used in the example configuration is a S7-1500, but a S7-1200 can be substituted for your own project.. It will be easy to start with a single I-device, and add the next two as an extension of the project.

Hope this helps,

Daniel Chartier

What i miss in I-Device

How addressing work and called by logic.

say if i have at the master plc physical out is Q0.0 to Q0.7

and if if at the slave i have a physical module with 8 digital out

how i'll use or call this outputs in my logic.

Hello Engea;

Have you opened the suggested document on I-device configuration?

You will find in clear terms how the configuration is defined and how the input/output addresses are linked between the I-device and the IO Controller.

Read the section "Testing the I-device function" for an example of how the configuration is checked.

Hope this helps,

Daniel Chartier

Yes i read it.:)

What i'm asking is :

if i want to use the physical output of the i-device i should call it from the program by the new address assigned to it, also i need to write a small program to define each i/o in the i-device to the corresponding in the controller. 

Hello Engea;

Once the I/O of the I-devices have been configured and associated with the I/O of the IO controller, you use these controller I/O addresses directly in the controller program, as if they were part of the controller's distributed I/O.

Hope this helps,

Daniel Chartier 

I did it and worked for digital [snip]