Functional Safety Network with Safety Drive System

This reference design features a safety motor drive with safety protocols in industrial systems. The design includes two independent RX72N 32-bit microcontrollers (MCUs), so if the system hits an unwanted stage, control is maintained and power to the motor can be safely cut.

The safety data, such as the emergency stops, comes from the safety sensor or safety programmable logic controller (PLC) through the industrial network communication block. This safety data is checked by both RX72N MCUs individually and if either shows an “emergency situation,” either one (or both) RX72N MCUs can cut off the motor power to avoid dangerous situations.

The safety control block consists of two RX72N MCUs, which manage motor emergency, stop control and safety protocol data processing. According to the safety international standards (IEC 61508, ISO 13849-1), it is required to have redundancy in the system, which we achieve by having dual RX72N MCUs. Each RX72N MCU operates the same process and they are able to check each other through the cross-monitoring interface.

System Benefits:

• Renesas supports required software for the safety control block, such as self-test software and control software system (self-test software kit and SIL3 system software kit). By using these safety solutions, customers can shorten their development and certification time and reduce their costs.
• By separating the safety functional block from the non-safety block (network device or motor control device), customers can easily design their applications
• Customers can select the best fit MCU for this safety system depending on the performance requirement from our wide RX Family portfolio.