Hi,

Сan I use only one channel on PM240-2 (eg. only STO_A), activated via DIP-switch

(photo attached)?

I don't need any special Safety Function, I just need to be guaranteed to block/stop drive,

for this I usually open the linear contactor, but now I would like to use special inputs (STO).

Technology Team

Hello,

for the use of the safety integrated function STO you have to use both inputs.

But you can use an one wire connection connected to STO_A & STO_B if the components are in one cabinet, check chapter 4.4.3.2 of the safety integrated manual.
https://support.industry.siemens.com/cs/de/en/view/109757227

 thanks, I'll do it, connect two channels STO_A&B to one NC contact (as attached),

only I will use a normal relay (not emergency)