schmersal PSC1-C-10 Series Installation Manual page 59

Installation manual
Safety instructions:
•
The error can be optimised by the suitable selection of the sensor resolution for the related
application.
•
For applications with limited resolution and/or time variance in the sampled signal, the
functionality of the monitoring functions used can be improved by the usage of a mean value
filter. Digital interference from the sensors is "smoothed" by the mean value filter. However,
this is achieved at the cost of an increased response time for the overall system.
•
The filter time can be set to between 0 and 64 in steps of 8. The dimension is "ms". To
determine the response time of the overall system, the filter times must be added to the
response times stated for the PSC1 system (see section 11).
Safety instructions:
•
For a safety-related assessment of the sensor sub-system, the information from the
manufacturer (MTTF
•
If specific diagnostics are required by the manufacturer to safeguard the safety-related
characteristic values stated, these are to be checked as per the above table "Specific diagnostic
measures for position and speed sensors" in relation to the specific encoders. If in doubt,
clarification by the manufacturer is required.
•
The DC values stated in the table are to be used conservatively and compliance with the
boundary conditions (see "Comments" in table) ensured.
•
To determine the DC for safety functions with standstill monitoring, among other aspects it is
necessary to estimate the frequency of the dynamic state. As a general figure a DC of 90% can
be assumed.
•
Fault exclusions are allowed according to the applicable standards. The boundary conditions
listed are to be ensured over the long-term.
•
If several sensor systems are necessary for the correct function of an individual safety
function, their partial values are to be combined correctly according to the method selected.
This statement also applies to a combination of digital and analogue sensors (e.g. safely
limited speed with safety door open = door contact + encoder for speed acquisition)
•
By means of the suitable selection of the resolution of the sensor system, an adequately low
tolerance in relation to the shutdown thresholds for the individual safety functions is to be
ensured.
•
On the usage of the encoder input filter, the increase in the response time is to be considered
during the assessment of the safety-related function.
PSC1-C-10 Installation manual V2.6
Version: 57E
, PFH figures etc.) is to be used.
D
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