Communication and data exchange between safety PLC and SCADA can be done by using Unrestricted memory area of Safety CPU.
Unrestricted Memory Area Description:
The unrestricted memory area (UMA) is a specially dedicated memory area for bits and words
which is not write protected. It has the following characteristics:
- It is located at the beginning of the complete memory range.
- Its size can be configured in Unity Pro XLS.
- Its values cannot be used directly but by using specific function blocks.
Basically we have two communication blocks S_WR_ETH and S_RD_ETH which tie into the NOE771 and its IO scanning capability.
This is the only mechanism that will allow communications outside of the safety PLC.
These restrictions and those mentioned above are part of the TUV /SIL3 certification requirements. You have a very limited number of blocks that will allow you to pass info in and out of the safety loop.
Unrestricted Memory Area Description:
The unrestricted memory area (UMA) is a specially dedicated memory area for bits and words
which is not write protected. It has the following characteristics:
- It is located at the beginning of the complete memory range.
- Its size can be configured in Unity Pro XLS.
- Its values cannot be used directly but by using specific function blocks.
Basically we have two communication blocks S_WR_ETH and S_RD_ETH which tie into the NOE771 and its IO scanning capability.
This is the only mechanism that will allow communications outside of the safety PLC.
These restrictions and those mentioned above are part of the TUV /SIL3 certification requirements. You have a very limited number of blocks that will allow you to pass info in and out of the safety loop.
Released for:Schneider Electric India
