PDF is the abbreviation for proximity devices with defined behavior under fault conditions; it designates a proximity switch with defined behavior (DIN EN 60947-5-3).
PDFs are subdivided into four groups:
PDF-D
Proximity switches with reliability due to their special design.
(Proximity devices with defined behavior under fault conditions – designed reliability)
PDF-T
Proximity switches with test capability.
(Proximity devices with defined behavior under fault conditions – test capability)
PDF-S
Proximity switches with single-fault safety.
(Proximity devices with defined behavior under fault conditions – single-fault tolerance)
PDF-M
Proximity switches with self-monitoring.
(Proximity devices with defined behavior under fault conditions – self-monitoring)
