Don't find pid 3_step for step 7 v5.5

Hello mugurelgi5;

If you open the online help files for FB41 and SFB41 (Cont_C), you will see it is the same file. So the function blocks are the same.

You can use one or the other, except for one thing: not all SFBs and SFCs are actually available on all CPUs of the S7-300 family. If you look at the attachment below, taken from the S7-300 Instruction list manual, you will see that the CPU 312 for example has not been setup to run SFB41. If you have such a PLC, opening the Blocks folder online will confirm that is is missing in the integrated blocks of the CPU.

https://support.industry.siemens.com/cs/ww/en/view/31977679

So if your CPU does not directly support SFB41, you can use FB41, but it will require a bit more memory in your program.

Hope this helps,

Daniel Chartier

Edit: for heating applications with ssr relays with a PWM output, check out FB 58 TCONT_CP:

https://support.industry.siemens.com/tf/WW/en/posts/continous-temperature-control-with-fb58-tcont-cp/19163?page=0&pageSize=10

 D.C.