Understanding D4NS-4CF safety switch

I am not sure how this switch works. Here is the URL for the data sheet CSM_D4NS_D4NS-SK_DS_E_9_7 (omron.com)

I am going to use the 2NC/1NO contact configuration. As I read this, when the key is inserted (safety door closed) the 2 NC switches will be closed and the NO switch will be open. Likewise, when the door is open the 2 NC switches are open and the NO is closed.

Am I correct or is this the opposite??

I’d agree with that reading of the documentation; the key-inserted state does appear to be the one considered “normal.” Considering the application, it’s a convention that does make some sense.

Thanks. I have another question. The Mechanical Engineers claim this switch also latches, meaning the door cannot be open during operation. I see absolutely NOTHING in the documentation that this switch works this way. I am going to look for a latched solenoid to do this.

The switch in question is intended for monitoring only, and does not provide any sort of locking function; to do so would require additional specifications to communicate the usage and limitations of the locking mechanism.

“latched solenoid” is perhaps a search term likely to generate mixed results for the sort of application in question. Assuming the intent is to prevent opening of a door/panel while a machine is in an unsafe condition, an electric door strike or electromagnetic lock may be more in keeping with the desired function.