Installation manual
Page 18 of27
5.1.2 Single-pole switching relay with external switching amplifier and testing
If you are using only one relay output, you will need a set-up to test the complete chain, i.e.
including all the downstream electro-mechanical, pneumatic or hydraulic components as well
as a message/warning device if faults are detected to achieve PL c or above.
You need positively guided auxiliary contacts for downstream electro-mechanical devices
or failsafe alarm contacts for the valve position for the hydraulic or pneumatic components.
The message/warning device must ensure that the operator recognizes the dangerous
situation immediately.
The achievable PI mainly depends on the test rate, PI d acc. to EM 13849-1 can be achieved
at a maximum.
X17
X14
K1
K2
IO01
IO02
P1
P2
X12
DI01
DI02
DI03
DI04
L +
L -
X17.1
X17.2
X17.3
X17.4
X14.1
X14.2
X14.3
X14.4
X12.1
X12.2
X12.3
X12.4
X7
K1/11
K1/12
K2/11
K2/12
X7.1
X7.2
X7.3
X7.4
Fig.: Single-pole relay output with testing
Safety note:
Only conditionally recommended for safety applications! In this context see also the
notes in EN 13849-1 concerning the application and the required fault exclusions.
For PL c or above, a test rate > 100 * request rate is necessary. For Pl d, you must
carry out testing at least once a year.
For PL c and above, a message/warning feature is required that informs the operator
immediately about a dangerous situation.
