Phoenix Contact 2986229, User Manual, Page: 40 / 102

PSR-TRISAFE-S
3-8
PHOENIX CONTACT 103503_en_03
As input signals with even and odd IDs are processed in different ways in the safety module,
using dual signals ensures that the safety module will perform redundant processing.
Two-channel sensors To ensure signal redundancy, the prepared dual signal must be used to process two-
channel signals (2-wire sensors and control devices). For example, in order to monitor or
evaluate both signals of an emergency stop control device redundantly and to performance
level PL e according to DIN EN ISO 13849-1 or EN 954-1 category 4, these two adjacent
signal inputs (e.g., I0 and I1) must be connected.
Cross-circuit detection A "cross circuit" is an unintentional, incorrect connection between redundant circuits. The
PSR-TRISAFE-S safety module provides clock outputs T0 and T1 as an aid for detecting
such a cross circuit.
For example, if two differently clocked signals are routed back to two inputs of the safety
module along two channels via an emergency stop control device, a cross circuit can
definitely be detected in this emergency stop circuit: In the event of a cross circuit, the same
clock signal would be present at both inputs, instead of two different ones.
The SAFECONF configuration software specifies the clock signals to be used: Cross-circuit
detection is implemented with test pulse T0 for "even" inputs (I0, I2, I4, ... I18). For "odd"
inputs (I1, I3, I5, ... I19), test pulse T1 must be used for cross-circuit detection.
3.4.2 Safe outputs
The safety-related outputs O0 to O3 are designed as digital semiconductor outputs for
24 V DC/2 A (total current), up to category 4 according to EN 954-1.
The outputs are controlled according to the configured safety logic. The safe outputs are
linked to the safety logic that is used to control the outputs in the connection editor of the
SAFECONF configuration software. See also "Adding and connecting functions, functional
blocks, and signals in the safety logic" on page 4-11.
For an example of two-channel connection of an emergency stop control device with dual
signal and cross-circuit detection , please refer to Figure 2-4 in "Error detection in I/O
devices" on page 2-8.
To increase cross-circuit protection, outputs O0 and O1 can also be used in connection
with ground switching outputs O0- and O1-, see "Ground switching outputs O0- and O1-
" on page 3-10.
An appropriate protective circuit (diode or varistor) for safe outputs O0 to O3 is strongly
recommended.
The safe output signals are clocked with a test pulse of 1 ms.