LION I/O Modules
▪
Digital Inputs
48
9
Digital Inputs
The inputs capture sensor signals in the voltage range of DC 24 V…36 V (Part-
No. 803501) and DC 72 V…110 V (Part-No. 803502).
9.1
Error Detection
9.1.1
Fail safe
9.1.2
Testpulse
If an error occurs, the channel has the signal level “HIGH“. The signals are set in
the process and diagnosis data.
See "Process Data Image” on page 51.
If an error occurs, which can not be handled, the module will go into failsafe mode.
9.2
Safety Integrity
The SIL1 level can be reached if the signals are read in via one channel
architecture. If the signals are read in via two channel architecture, valent or
antivalent, the SIL2 level can be reached.
SIL
relevant
LION-038
For the error detection there are two diagnosis functions implemented:
Testpulse
To recognize “Stuck at high“ (1) errors.
Diagnosis Data Transmission via safe protocol to the PLC
The PLC checks the process and diagnosis data as well as the troubleshooting
SIL
relevant
LION-037
▪ The fail safe of the modules is defined as logic “0“ (LOW).
▪ If an input is not connected logic “0“ is recognized as an input value.
▪ If an error occurs the corresponding status bit is set to “1“ and the process
value of the input is set to the defined safe value (“Stuck at high“).
SIL
relevant
LION-041
All input signals, which are not in the safe mode are monitored cyclic with a test
pulse.
The testpulse is for detecting faults in the input circuit and ensures that the input
can read a “0“ signal.
The testpulse monitores the inputs for errors:
“Stuck at high“: The inputs “1“-signal is covered by a short “0“-signal of the
testpulse and read back.
“Stuck at low“ is not monitored because it corresponds to the safe status.
Connected sensors are not tested. Errors which occure outside of the modules
cannot be recognized.
