SM811K01 secure CPU module redundancy

The SM811 K01 is a secure CPU module produced by ABB Group, whose main function is to provide intelligent monitoring

of the controller during non-SIL and SIL1-2 operation, and together with the PM865 forms a 1oo2 diversified structure for

SIL3 applications. For high availability applications, a redundant SM811 that works with either of the two redundant cpus can be used.

The SM811 has a dedicated synchronization link to synchronize active and redundant SMS for hot insertion and online upgrades.

SM811K01

In the PLC control system, the CPU module is equivalent to the human brain, which constantly collects input signals,

performs user programs, and rewrites the output of the system. Memory is used to store programs and data.

The operating voltage of the 3BSE018173R1 CPU module is generally 5V, while the input/output signal voltage of

the PLC is generally higher, such as 24V DC and 220V communication. The surge voltage

and interference noise introduced from outside can damage the components in the CPU module or make the PLC not work properly