In order to achieve the maximum safety performance level PLe, a category 3 or 4 architecture must be used. What this means for a servo system is that a second method for measuring speed is required; this is usually achieved by fitting an additional encoder or resolver to the axis, which also increases the costs and and adds complexity to the system and set-up procedure.
Thanks to its onboard safety card, the Pilz PMC Protego DS is able to measure the motor's own electrical output to determine its speed. This, combined with the feedback signal provided by any servo motor, constitutes a category 4 architecture. Using the PMC Protego DS drive and any servo motor, it is therefore possible to achieve PLe without any additional equipment.
The PMC Protego DS also has the following Safe Motion Functions included as standard:
- Safe Torque off
- Safe Stop 1
- Safe Stop 2
- Safe Operating Stop
- Safe Limited Speed
- Safe Speed Range
- Safe Direction
- Safe Limited Increment
- Safe Braking functions*
- Safe Limited Position*
* These last safety functions are available as additional options.
With free configuration software, the PMC Protego DS is straightforward to configure for motion tasks and safety features alike. Follow the link for more information about the Pilz PMC Protego DS.