Chapter 1 Overview - Mitsubishi Electric MELSEC iQ-R Series Safety Function Block Reference

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OVERVIEW
Safety FBs are the manufacturer offer function blocks that received the certification of ISO13849-1:2015 PLe, IEC62061:2012
SIL3, and IEC61508:2010 SIL3. The safety FBs can be used with the MELSEC iQ-R series safety CPUs.
Improving the productivity and the maintainability of a safety program
The major functions used in programming safety applications are provided as the safety FB library. A safety program
becomes simple by using the safety FBs, and the productivity and maintainability of the safety program are improved.
Moreover, efficiency of debug and verification for a safety program is also improved.
The high safe level application using the safety certified FB
Since the safety FB received the safety certification, a user can build a safety application which is in compliance with
ISO13849-1:2006 PLe, IEC62061:2012 SIL3, and IEC61508:2010 SIL3. A user can develop an advanced safety application
using the safety FBs, and it becomes easy to get the safety certification of user's safety application from an inspector.
Improving the reliability of the safety program
Since users cannot read the inside logic of the safety FBs, the users cannot customize or modify them. Therefore, the safety
FBs cannot be intentionally modified by an intentional or mistaken operation and the reliability of a safety feature of a program
will improve. Also, a safety FB used is whether the certified one or not can be identified by its name because the safety FBs
and their name cannot be created and changed by a user.
Displaying a diagnostic code
The diagnostic code includes error codes and status codes. When a safety FB detects an internal error (including out of range
of parameters and invalid static Reset), it displays an error code. When no error is detected, a safety FB displays a status
code. Diagnostic codes are useful in knowing the operating status of the safety FBs and debugging.
Combination with a ladder
Safety FBs can be used within a ladder diagram. By combining a popular ladder and the certified safety functions, a user can
make a safe and highly flexible safety program.
1 OVERVIEW
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