5
CSS 30S
CSS 300
Operating instructions
Safety sensor
EN
6.2 Operating principle of the electronic diagnostic output
The short-circuit proof diagnostic output can be used for central
visualisation or control functions, e.g. in a PLC.
The electronic diagnostic output signals faults before the safety outputs
are disabled, thus enabling a controlled shutdown.
The diagnostic output is not a safety-related output!
The diagnostic output can also be used to detect clearance variations
between the sensor and the actuator in the same way as the yellow
LED. An active fault causes the diagnostic output to be disabled. The
safety outputs are disabled after max. 30 minutes if the fault is not
rectified. The signal combination, diagnostic output disabled and safety
channels still enabled, can be used to stop the production process in a
controlled manner.
Error
A fault has occurred, which causes the safety outputs to be disabled.
The fault is reset, when the cause is eliminated and bit 7 of the request
byte changes from 1 to 0 or the safety guard is opened. Faults at the
safety outputs are only deleted upon the next release, as the fault
rectification cannot be detected sooner.
Error warning
A fault has occurred, which causes the safety outputs to be disabled
after 30 minutes. The safety outputs initially remain enabled. This
enables the shutdown of the process in a controlled manner. An error
warning is deleted when the cause of error is eliminated.
Table 1: Examples of the diagnostic function of the safety-sensor with conventional diagnostic output
System condition
Duo LED
green red
LED
yellow
Diagnostic
output
Safety
outputs
Y1, Y2
Note
Supply voltage on, not actuated
On
Off
Off
0 V
0 V
Voltage on, no evaluation of the voltage quality
Actuated
On
Off
On
24 V
24 V
The yellow LED always signals the presence of an
actuator within range
Actuated in limit area
On
Off
Flashes
24 V
pulsed
24 V
The sensor must be adjusted before the distance to
the actuator increases and before the safety outputs
are disabled, thus stopping the machine
Actuator, error warning
Off
Flashes
On
0 V
24 V
The safety outputs are disabled after 30 minutes
if the error is not rectified.
Actuated, fault
Off
Flashes
On
0 V
0 V
Refer to table with flash codes
Actuated, internal fault
Off
On
On
0 V
0 V
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6.3 Safety-sensors with serial diagnostic function
Safety sensors with serial diagnostic cable have a serial input and
output cable instead of the conventional diagnostic output. If safety
sensors are wired in series, the safety channels as well as the inputs
and outputs of the diagnostic channels are wired in series.
Max. 31 sensors can be wired in series. For the evaluation of the serial
diagnostics line either the PROFIBUS-Gateway SD-I-DP-V0-2 or the
Universal-Gateway SD-I-U-… are used. This serial diagnostic interface
is integrated as a slave in an existing field bus system. In this way, the
diagnostic signals can be evaluated by means of a PLC. The necessary
documentation for the integration of the SD-Gateway is available for
download at www.schmersal.com.
Accessories SD interface
For ease of wiring and series-wiring of SD devices,
considerable accessories are available. Detailed information
is available on the Internet, www.schmersal.net.
The response data and the diagnostic data are automatically and
permanently written in the assigned input byte of the PLC for each
safety sensor in the series-wired chain. The request data for each
safety sensor are transmitted to the device through an output byte of
the PLC.
In the event of a communication error between the field bus Gateway
and the safety sensor, the switching condition of the safety output of the
safety sensor is maintained.