HB-37350-810-01-50F-EN PSC1-C-10 Installation manual V2.1.docx Page 52 of 189
Version: 50F
On the usage of a single-channel sensor with test pulses, one connection is connected to the
test pulse output T0 or T1 of the PSC1. The pulse assignment must then also be carried out in
SafePLC2.
The usage of a single-channel sensor with test pulses detects:
Short-circuit to the supply voltage DC 24 V
Short-circuit to DC 0 V
Cable break (interruption of power is safe state!)
Caution is required, on the other hand, if there is a cable short-circuit between the two
connections for the sensor, as this will not be detected! A short-circuit between T0 and I00 is
also not detected.
Due to the single-channel character of the switching element / sensor, a fault exclusion is
required for its failure. This exclusion is allowed on the usage of positively opening switches
with correct positive actuation.
The series connection of 2 switching elements with corresponding fault exclusion for a double
fault is the same as this application (occurrence of two faults at the same time). This could
represent, e.g. the safety outputs on an electronic monitoring device (light curtain, safety mat)
with internal dual-channel shutdown.
On the usage of a suitable switching element and careful wiring of the sensor, PL d according
to EN ISO 13849-1 can be achieved. In special cases, i.e. in conjunction with suitable
switching elements and permissible fault exclusions, PL e according to EN ISO 13849-1 can
be achieved.
Safety instructions:
PL d or higher according to EN ISO 13849-1 is achieved if a short-circuit between the
input and related pulse output as well as a short-circuit between the sensor
connections can be excluded. Here it is to be noted that in the event of a fault, the
switch must be positive opening according to EN 60947-5-1. In addition, the sensor
must be triggered at regular intervals and the safety function demanded. Fault
exclusions can be obtained as per EN ISO 13849-2 Table D8. On the single-channel
usage of the inputs, the safety level that can be achieved is limited to SIL 2 or PL d, if
there is no demand for the safety function at regular intervals.
The connection in series of 2 switch elements with fault exclusion for a double fault
requires a check for suitability according to the safety level required for this element.
Reference is made to the applicable stipulation in the EC Machinery directive
2006/42/EC.
With single-channel sensors, in principle the safety-related usage of the inputs is only
intended in conjunction with the pulse outputs.
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