Analog I/O to Siemens and double PLC in Simumatik to Siemens


I´m trying to connect an analog sensor to Siemens tia v.16.
In Simumatik i have named the sensor in the var_AI1 (as an example) and i have the same name in the Analog In in the IO tags on my device configuration in Siemens.

In the Default tag table it shows and as an int but when i test it it gives nothing.

The third party software tutorial for Siemens did not give any information about this so i’m wondering if there is anyone here who has any ideas of what i might have missed?

Another question.
If i where to run out of inputs on my PLC in Simumatik and add another PLC, do i need to add another one in Siemens as well or will they be seen as one?
I´m using the PLCSIM Advanced 3.0

So i have figured out the first question by my self. As the PLC i’m using has three I/O units i had forgotten to turn the “process image” to “none” on the third.

I think i have also solves the second question and the answer is that they will be seen as one PLC, but as i have not look into it more than just a glimpse i’m open for other answers :slight_smile:



Regarding the second question, yes you can add multiple PLCs in Simumatik cinnected to a single physical (or simulated) PLC to get more variables, however there is a library with a “rack PLC” for Siemens, where you can add input and output cards, kind of like how you use a S7-1500 PLC, you can see if that suits your needs.

Use it by adding a PLC and connect the IO-cards needed and end with a rack end module, they are connected with serial input and outputs.


Hi Fabian,

I have a plan to practice a bit on a system with several PLC´s and so far the set-up works great, thank you for your help!