hi hash4m,

for the two devices you mentioned you don´t need an extra power-supply.

regards,

Siemens expects us to use the digital inputs and outputs available on the PLCs.  They expect us to even turn them all on at once time, and worst case, they expect us to turn all the digital outputs on at the exact same time and that each output draws the maximum allowable inrush current when first turned on.

If that is the case with your project, then yes, a 6A DC supply is required.  If you are not using any digital outputs, then sure, the 24V supply is not required.  That said, some day someone will ask you to use some of those outputs.

hash4m

Hi

I am not sure if I need a power supply or no.

I choice S7-1212 AC/DC/RLY 230v AC, with CM1241 RS485 communication module

from my point of view no need for a a power supply as it is working on 230V ac.

However, the TIA selection tool suggested me to have a power supply with at least 6A.

Could you please help