X20(c)SC2212
20
Data sheet V1.141 X20(c)SC2212 Translation of the original documentation
8.2.4 Connecting multi-channel sensors with contacts
The status of the connected switches is indicated by channel-specific LEDs. The LEDs "OO" and "OC" have no
significance with this type of connection.
With this wiring, the following errors can be detected:
Error
Ground fault on the pulse output
Detected
Pulse output shorted to 24 VDC
Detected
Cross fault between the pulse output and the other pulse signal
Detected
1)
Ground fault on signal input (active signal)
Detected
1)
Ground fault on signal input (inactive signal)
Not detected
Signal input shorted to 24 VDC
Detected
Cross fault between the signal input and the other pulse signal
Detected
1)
Cross fault between the pulse output and the signal input (active signal)
Not detected
Open circuit (active signal)
Detected
1)
Cross fault between the pulse output and the signal input (inactive signal)
Detected
1)
Open circuit (inactive signal)
Not detected
Table 12: SI error detection when "Pulse Mode = External"
1)
Detected by PLCopen function block "SF_ModeSelector" in the application.
Danger!
If "Pulse Mode = External" is used in the channel configuration, then an additional TOFF filter with
5 ms is enabled in the module. The corresponding information regarding the TOFF filter must also be
considered when using the "Pulse Mode = External" setting.
Information:
With the configuration "Pulse Mode = Internal", the pulses have a low phase of approximately 300 µs.
This low phase is designed such that no additional degradation of the total response time can occur in
the system. If line lengths exceed the max. line length (see technical data), problems may occur with
this configuration. In these cases, configuration "Pulse Mode = External" can also be useful for normal
sensors with contacts. The reduced error detection and extension of the total response time must be
taken into account, however.
8.2.5 Connecting electronic sensors
A pulse pattern cannot be used with electronic sensors. The input channels must therefore be configured to
"Pulse Mode = No Pulse".
Any gaps when testing the connected OSSD outputs must be masked out with the module's cutoff filter in order
to avoid an unintended shutdown.
Danger!
With the configuration "Pulse Mode = No Pulse", the module itself is not able to detect wiring errors.
Internal errors are still detected, however. All errors resulting from incorrect or faulty wiring must be
handled through supplementary measures per EN ISO 13849-2:2012 or by the connected device.
Danger!
Configuring a switch-off filter lengthens the safety response time. The configured filter value must be
added to the total response time.