First, for A6 servo drives equipped with the STO function, no additional equipment is required to activate the STO function. The STO function is enabled by default when the drive leaves the factory. Both STO1 and STO2 are set to "Low". When the drive is powered on for the first time, "STO" will be displayed, as shown in the wiring diagram below:
Connect a 24 V power supply and install a switch in the circuit to freely control the "High" and "Low" states of STO.
Of course, this is only the simplest connection method. There are two common methods:
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Use a dedicated safety PLC, which is suitable for medium and large systems with complex safety logic, such as switching between multiple safety modes and multi-axis coordinated safety control.
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Directly use a safety relay to output two independent 24 V digital safety signals to control the STO state of the drive. This method has simple logic and very low cost per node, making it suitable for small systems.
The STO response time will not exceed 30 ms. For vertical-axis applications, this time is reduced to 5 ms.