schmersal PSC1 - Overview of Achievable PL for Digital Safety Outputs

Installation manual
HB-37420-810-01-25F-EN PSC1-C-100 Installation manual - V2.2.docx Page 93 of 201
Version: 25F
4.3.5.3 Overview of achievable PL for digital safety outputs
Output
PSC1
Actuator /
external
shutdown
circuit
Catego
ry
accord
ing to
EN ISO
13849-
1
DC MTTF
d
actuat
or
Achie
vable
PL
accor
ding
to EN
ISO
13849-
1
Boundary condition Fault
exclusion
Single-
channel
without
dynamic
output test
Qx
Q0_P, Q1_N,
Q2_P, Q3_N
IQQx
Single-channel
Contactor, valve,
brake etc.
without direct
feedback for
diagnostics
Cat. B 0 % Medium B Contactor and
downstream actuators
suitably designed for
safety application
Single-channel
Contactor, valve,
brake etc. with
monitored,
positively driven
auxiliary contact
Cat. 2 60-
90%
Depende
nt on
switching
frequenc
y
Medium B Signal output required
for warning if malfunction
detected
Contactor and
downstream actuators
suitably designed for
safety application
High C As before
D As before
DC = 90% due to
adequately high test rate
in relation to the
application
Single-
channel
without
dynamic
output test
Qx
or
Single-
channel
Q0_P, Q1_N,
Q2_P, Q3_N
Dual-channel
Contactor, valve,
brake etc. with
direct feedback
for diagnostics in
at least one
channel
or
Actuator
operated with
single channel
with safety
function cat. 3
(e.g. STO)
Cat. 2 90% Monitorin
g only in
one
external
shutdown
circuit
Medium c Signal output required
for warning if malfunction
detected
Contactor and
downstream actuators
suitably designed for
safety application
Short-circuit
on external
operation
High d
Single-
channel
without
dynamic
output test
IQQ00
..IQQ09
Dual-channel
Contactor, valve,
brake etc. with
direct feedback
for diagnostics in
at least one
channel
or
Actuator
operated with
single channel
with safety
function cat. 3
(e.g. STO)
Cat. 3 90 % Monitorin
g only in
one
external
shutdown
circuit
Medium
or high
d Contactor and
downstream actuators
suitably designed for
safety application
Short-circuit
on external
operation
Single-
channel with
dynamic
output test
IQQ00
..IQQ09
Dual-channel
Contactor, valve,
brake etc. with
direct feedback
for diagnostics in
both channels
or
Actuator with
safety function
cat. 4 (e.g. STO)
Cat. 4 99% Monitorin
g in both
external
shutdown
circuits
High e Contactor and
downstream actuators
suitably designed for
safety application
Monitoring
electromechanical
components by means of
positively driven
switches, position
monitoring on switching
valves etc.