The modular PLC series "Melsec iQ-R" from Mitsubishi Electric There is now a fully redundant control pair with maximum performance and reliability. To reduce the total cost of ownership, various safety and security monitoring and control functions are also integrated into the PLC.
In recent years, compliance with international safety standards has become an indispensable requirement for success in global markets. In addition, fast system recovery after controller failures has proven to be an important criterion. Many centralized applications in production therefore require full redundancy in accordance with the 2 (Safety Integrity Level 2, SIL 2) safety standard according to IEC 61508, so that the critical systems remain functional even in the event of a failure or accidental damage to the primary CPU unit.
According to TÜV Rheinland certification, the SPS redundancy pair Melsec iQ-R meets the requirements of this standard for functional safety for the international market. The guidelines within the redundancy standard require a fully duplicated PLC enclosure with all modules that can be switched immediately if the primary system fails.
The GX Works3 programming platform provides a common programming environment for both process and safety control. This enables the execution of integrated process and safety control programs with only one CPU module, eliminating the time and expense of purchasing and installing a separate safety controller.
Process safety and reliability are the main reasons for plant operators to install redundant automation controllers in their systems. Therefore, the basic redundancy architecture of iQ-R has been extended by another layer of protection. In addition to the power supply module, the base unit and the network module, the safety version of the PLC includes a set consisting of a SIL 2 process CPU module and a separate SIL 2 function module. This ensures continuous operation by switching to standby mode in the event of a fault in the controller.