Hello,
We are developing an application with SPLC with Visu+ HMI for gas detection system. Usually we have predefined levels for gas alarms, such that if gas concentration exceeds alarm limit the alarm is activated with corresponding outputs by SPLC. The client wants to be able to change the alarm limits in HMI, but is there a way to this in a SIL application (since OPC UA is non-SIL)?
Here is the answer from the Safety support team:
_Basically, the HMI is not a safety component.Therefore, simply specifying safety values via the HMI is not permissible from a safety point of view.A possible solution would be to check the plausibility of defined limit values in the safety program.Example:= > Input of a limit value via the HMI _= > Plausibility check of the input via the safety program.= > If the value is invalid, an error is output and a valid safe limit value is specified from the safety program._= > If the limit value is valid, it is mirrored back to the HMI and the user must confirm the value again if necessary.____Does the example describe your requirements?__What would be your concrete requirements?___Another topic is the remanence of safe data. This is not yet supported by the SPLC1000. However, there are applicative solutions for this.
If you would like someone to contact you directly to discuss this application, please let us know.