s7 1200 communication help

Hello,


Need help as I want to connect two s7 1200 cpus to extend I/O numbers.
The network will be 2 s7 1200 cpus and a regular pc as HMI.
What the best network configuration for it.

How much data are you transferring?

For up to a reasonable amount (256 bytes), I would use profinet with GET/PUT connection.

For get/put as I understand I need to to write a program to convert the data to the required I/O.
If right, is there's a way more simple so once I configure the network I can use all the modules directly.

You could set one up as an iDevice and read and write directly to it's IO.

Why not just buy remote IO rather than 2 S7-1200?

Or are you just working with what you've got.

Unfortunately yes I'm working with the available components.
I didn't configure an IDevice before.
Could you guide me through it.

https://cache.industry.siemens.com/...8798_config_idevice_standard_DOCU_V1d0_en.pdf

You should find everything you need in this .pdf

Thanks alot

I read it and understood the configuration criteria.
What I'm missing is when writing the logic how I'll deal with IO addressing for the IDevice.
For example if I've an input and output coil.
How I'll address this in the ladder.

Just use the I and Q bits configured in your hardware config.

.......I0.0.....................Q0.0
------| |-------------------( )

So if I've for the controller 8 bit out card

And the IDevice 8 bit out card
This mean if I want to call output from IDevice it will start from Q1.0
if the one at the I/O controller start Q0.0
Am I right

In the device that is providing its I/O you have to copy over states to/from the i-device from/to the physical i/o.

So, if you have for example:
Master PLC outputs configured for the slave PLC, Q100.0 .. Q101.7
Master PLC inputs configured for the slave PLC, I100.0 .. I101.7
Slave PLC i-device inputs I100.0 .. I101.7
Slave PLC i-device outputs Q100.0 .. Q101.7
Slave PLC physical outputs Q0.0 .. Q1.7
Slave PLC physical inputs I0.0 .. I1.7

In the Slave PLC you must program this:
I100.0 --> Q0.0 // from i-device inputs to physical outputs. edit: Possibly use DPRD_DAT for this, see below.
I100.1 --> Q0.1
etc.
I0.0 --> Q100.0 // from physical inputs to i-device outputs. edit: Possibly use DPWR_DAT for this, see below.
I0.1 --> Q100.1
etc.

In the master PLC when Q100.0 is activated, then Q0.0 in the slave PLC will activate.
And when input I0.0 in the slave PLC activated, then input I100.0 in the master PLC will activate.

edit: Not sure if it is an issue or not, since I dont have experience with S7-1200.
If the i-device addresses are outside the process image of the CPU, you must transfer all the data in one go (i.e. "consistently").
For this purpose you would use DPRD_DAT and DPWR_DAT system functions.
I just mention this for completeness sake. If you assign i-device addresses at the low end, you can just copy the addresses the normal way.

Ok
I'll give it a try and feed u back.

I still have some conflict with the addressing for I-Device but I'll give it a try.

Thanks

Cannot two S7 1200's just Modbus TCP/IP configure to talk information back and forth?

Thanks
I did it and worked for digital

But my problem now for analog IO

Any help