How many 230VAC inputs do you need?  2 SPDT interface relays and you have essentially used the same space as a 230VAC signal module for the s7-1200.

Modules for the s7-1200 are generally rather inexpensive for what you get.  Also, they are relatively small "height-wise", and for the DIN rail space they are decent.

Also, if you are not aware, you can use an Expansion cable on S7-1200 to add modules to the S7-1200 rack when DIN rail width is too small, but a somewhat nearby DIN rail is available.  The cable connects the PLC bus from one module to the next.

AutoGen_2082234

Thank you. Are there other possibiltys? Such as small interface relays and such? 

I have a lot of inputs and this SM is quite expensive and take a lot of place in the cabinet.

Kind regards

AutoGen_2082234

Thanks a lot for all the help. I will have to stick with Siemens though. I need 49 inputs but only 15 outputs, that's why I think it's expensive. 

That is indeed many AC inputs. Here we classify such a machine as a danger. Things go wrong and sensors get damage. It would be much problem if the AC power 'leaked' into the framework of a station where the operator works.

All I can say: Good luck doing the job.

In that case, I recommend ~50 opto-isolators that convert 230VAC to 24VDC.  Some of them are intended for PLC use.  Others are not.  It is easy to tell the difference once wired.  If it works with on and off signals, it is intended for PLC use - or something with similar input impedance.  Otherwise, you need either 1, 2, or 3 resistors on the output to make the 24V and 0V signals function properly for PLC input impedance. 

opto-isolators are generally sized similar to WDU2.5 Weidmuller terminals, so that's a lot of DIN rail space.  I would recommend placing the 230VAC inputs far away from any analog signals.

If possible, I recommend using Remote IO to handle the 230VAC inputs, if I am guessing correctly and these inputs are not in the same enclosure as the PLC.  That will keep the high voltage AC out of the enclosure and make it easier to manage the EMI imposed on analog signals.

AutoGen_2082234

Thanks a lot for all the help. I will have to stick with Siemens though. I need 49 inputs but only 15 outputs, that's why I think it's expensive.