Rockwell Automation Publication SAFETY-AT140A-EN-P - May 2015
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Safety Function: Actuator Subsystems – Stop Category 1 via the PowerFlex 525 and PowerFlex 527 Drives with Safe Torque-off
This can be modeled as follows:
The rest of the SISTEMA calculation in this document features a SensaGuard switch as an example of a typical safety input
device.
For instance, when the PowerFlex 525 drive is used, these are the SISTEMA calculations for the safety function, "Safety-
related stop function initiated by a safeguard:"
When the PowerFlex 525 drive is used in the safety function, "Prevention of an unexpected startup," the SISTEMA
calculations are identical, because all of the same components are used.
Logic
Output
Subsystem 1
Subsystem 2
Subsystem 3
Guardmaster
Dual-input
Safety Relay
Guardmaster
Multifunction-delay
Expansion Module
PowerFlex
527 Drive
