U-ONE
®
-SAFETY Compact
Configuration manual SCU C / SRC C / SGS C
22
USC42_SCU-KonfigManual-en_R5
6.1.2 Digital outputs
There are 2 digital outputs: Status and error output.
Both outputs are 2 channel (Cat. 3) types. Both channels
of an error output must have the same status
(open/closed) and both must be monitored by the applica-
tion. An error will be flagged if the channels are not the
same.
•
Error output:
When the status is error-free both channels of the error output are high and transmit
test pulses (factory setting see Fig. 6-3). The USC 42 monitors the output to ensure it
is functioning properly.
CAUTION!
If the error output is utilized to detect a device error it must be subject
to a safety-related evaluation (see document “USC 42_Manual-en_R..”
Chapter: Application examples).
The receiver must suppress the test pulses to avoid unwanted switching operations.
- The following settings are available to set the duration of the test pulses:
100 ms, 10 ms, 1 ms, off (factory setting: 1 ms).
- For the quotient ‘test pulse interval / test pulse duration’ (T/ti) it is possible to select
10, 100, 1000 (factory setting: 1000).
- The test pulse offset (test pulse offset between channels) tc = 2* ti cannot be set.
For non-safety relevant applications it is possible to deactivate the test pulses. An
error is indicated by a low-level signal at the error output, which can only be reset via
the configuration software "US42Pro" (factory setting). It is possible to set the error
performance via the software so that an error will also be reset by interrupting the
supply voltage (> 2s) or by initiating a reset at the reset input).
The reset always initiates a system reboot including a complete system test. If an
error is determined again, the device remains in an error condition. Error logs are
saved in the error memory.
CAUTION!
The "fault reset via the reset input or power supply interruption" option
may be used only if a risk analysis has shown that the application is
suitable.
•
Status output:
The status output indicates the operating status in conjunction with the error output of
the USC 42 (see separate operating and assembly instructions. Chapter: Operating
conditions and indicators). The status output does not issue any test pulses.
Fig. 6-3: Error output
