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8024493/AE00/V1-0/2020-09| SICK
O P E R A T I N G I N S T R U C T I O N S | DUSTHUNTER SP100 Ex-2K
Subject to change without notice
3
PRODUCT DESCRIPTION
3.3.9
Function check
A function check can be triggered at fixed intervals to automatically check the function
(check cycle) of the measuring system. The start time for the automatic function check
begins when the device is switched on. Any unallowed deviations from normal behavior that
may occur during function monitoring are signaled as errors. A function check triggered
manually can help localize possible error causes should a device malfunction occur.
The function check comprises:
●
Approx. 45 s measurement of zero value, control value and contamination of optical
surfaces
The measuring time depends on the increase in contamination value (change > 0.5%
→
measurement is repeated up to 2 times).
●
Every 90 s (standard value) output of values determined (duration parameter can be
modified,
see “Determining the function check”, page 73
).
Fig. 10: Function check output on a plotter
Zero value measurement
The sender diode is switched off for zero point control so that no signal is received. This
means possible drifts or zero point deviations are detected reliably in the overall system
(e.g., due to an electronic defect). A warning signal is generated when the “zero value” is
outside the specified range.
Control value measurement (span test)
Sender beam intensity changes between 70 and 100% during control value determination.
The brightness of the light signal in the measuring circuit (“measuring signal”) is compared
with the brightness in an independent internal reference channel (“monitor signal”). The
measuring system generates an error signal for deviations greater than ±2%. The error
Contamination degree
(Live Zero = 0%, at 4 mA
on analog output)
Function check
start
Zero value output (Live Zero)
Control value output
(70% value, span)
Contamination output
Control value
determination
Paper feed
Function check
end
●
The analog output must be activated to output control values on the analog output
(
see “Setting the analog outputs parameters”, page 74
).
●
The value measured last is output on the analog output during control value
determination.
●
If the control values are not output on the analog output, the current measured value
is output when control value determination has completed.
●
“Function control” is displayed on the control unit display during the function check.
●
A function check is not started automatically when the measuring system is in
“Maintenance” mode.
●
If the cycle interval is changed, a check cycle timed between parameter setting and
new start timepoint is still carried out.
●
Changes to the interval time are first effective after the next start timepoint.