VulpesLago

NX1P2 SIL

9 posts in this topic

Hello!

I have problem with nx1p2 SIL/pl rating.

crane standard says, system have to be atleast (EN ISO 13849) PL D or (IEC 61508-1) SIL 2 rated.

Did not found answer from the manual or google. Full Safety rated system is too expensive for this application. 

Long story short does anyone know SLI rating for nx1p2? Is there any SIL 2 rated cpu's?

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SIL and PL ratings are for safety PLCs, not applicable to standard PLCs like NX1P2.

Category and PL are defined by ISO 13849-1.

SIL is defined by IEC 61508.

The NX-SL safety controllers are rated SIL3, PLe

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If you are looking for safety on a budget the G9SP safety PLCs would be a good route.

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Hi!

update on this case. System for this device had to be only pl C

 

 

We can use Nx1p2 cpu for "safety" systems. But we have to make external safety calculation and fulfill standard requirements. Also we need to have external Test channel. 

 

In my case there is only one safety related analog input. We will use external Analog value switch, to fulfill standard 13849 category 2 requirements (picture in attachments).

We also make sistema risk assessment for the system. If mttfd-value (mean time to dangerous failure) is high enough we can use nx1p2-cpu.

 

Long story shot. If you use two differend systems to monitor and control the safety system, it might be possible to use non safety rated systems.

 

Hope so this helps you in the future!

 

 

category 2.JPG

Edited by VulpesLago
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Might be possible to use non-safety devices, but sure not smart.  You need to be looking at G9SP.  

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On 14/03/2022 at 7:52 PM, Crossbow said:

Might be possible to use non-safety devices, but sure not smart.  You need to be looking at G9SP.  

Hello!

 

It does not have analog input for safety.

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2 hours ago, VulpesLago said:

Hello!

 

It does not have analog input for safety.

I don't know any safety CPU with an analog input.  Analog signals are not typical safety devices.

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Siemens S1200 safety series had one cpu with external analog I/o, but it was very expensive.

Load cell in overload protection on Eot cranes is very common. 

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