General Information About Enabling And Signaling Circuits - Siemens SIRIUS 3TK2810-0 Equipment Manual

1.3

General information about enabling and signaling circuits

Relay enabling circuits:
When a safety function is requested or a fault detected, the 3TK28 safety relays enter the safe
state. This means:
Relay enabling circuits with NO function OPEN
Relay enabling circuits with NC function CLOSE
Relay signaling circuits:
Relay signaling circuits always have NC functionality with 3TK28 devices.
Relay signaling circuits thus always operate inversely with respect to the relay enabling
circuits with NO functionality.
Solid-state signaling circuits:
Solid-state signaling circuits in 3TK28 safety relays signal the state of the enabling circuits (==>
functioning synchronously with the solid-state enabling circuits).
When a safety function is requested or a fault detected, the 3TK28 safety relays enter the safe
state. This means:
Solid-state signaling circuits switch to the inactive state.
3TK2810-0 standstill monitor
Equipment Manual, 08/2023, A5E50307927002A/RS-AA/001
1.3 General information about enabling and signaling circuits
Introduction
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